MapServer教程2

第二章 Tutorial 教程

MapServer Tutorial MapServer教程

• Tutorial background 教程背景
• Section 1: Static Maps and the MapFile 第一阶段：静态地图Maps和地图文件MapFile
• Section 2: CGI variables and the User Interface 第二阶段：CGI变量和用户界面
• Section 3: Query and more about HTML Templates 第三阶段：查询和HTML模板
• Section 4: Advanced User Interfaces 第四阶段：增强用户界面

Tutorial background教程背景

• Tutorial Timeframe 教程时间框架

虽然有些用户可以在一天内完成本教程，但那些详细研究每个示例的用户可能期望在一周内完成本教程。

• Tutorial Data 教程数据

本教程中使用的数据集取自美国内政部a zs美国国家地图集（现在由data.gov托管）。数据集被裁剪到上五大湖地区（明尼苏达州、密歇根州和威斯康星州），以减少存储空间。额外的光栅图像是由明尼苏达大学的Terrasip项目提供的。使用本教程时，鼓励您使用自己的数据集。

与MapServer本身一样，本教程对任何人都是开放的和可自定义的。这样做的目的是希望有人（或某些人）能够帮助设计和进一步开发它。

在http://download.osgeo.org/mapserver/docs/mapserver-tutorial.zip下载本教程的数据（以及所有HTML文件）。

• Before Using the Tutorial 在使用本教程之前

使用本教程有一些先决条件：
1。用户需要在其计算机上安装并运行Web服务器。此Web服务器必须支持通用网关接口（CGI）程序。
2。用户应该对Web服务器和Internet安全有基本的了解。配置不正确的Web服务器很容易被恶意的人攻击。你的软件安装会失败你zll会损失数小时的工作效率，最坏的情况是你的电脑可以用来攻击互联网上的其他电脑。
3。建议本教程的用户在继续此操作之前先阅读MapServer简介。
4。要使用本教程，用户需要在他们的系统。MapServer源代码可在此处下载。关于如何编译的文档已经存在并安装MapServer：
•对于Unix用户，请阅读MapServer Unix编译和安装指南。
•Windows用户应阅读MapServer Win32编译和安装指南
此外，许多平台都存在预编译的二进制文件（请参见下载页）。

Windows, UNIX/Linux Issues  Windows、Unix/Linux问题

Paths

路径

本教程是在Linux/Unix上创建的，但是应该在Windows平台上进行最小的更改。主要区别在于map文件中的路径。Windows用户需要指定其教程文件所在硬盘的驱动器号。这里是一个例子：

Unix地图文件可能包含如下参数：

在Windows中，相同的参数可能如下所示：

或者：

请注意，斜杠或反斜杠在Windows中都有效。如果您想区分映射文件中的虚拟路径（如URL或Web地址）和本地路径，通常的反斜杠可能对您很有用。但是，如果您计划在某个时间点将应用程序移动到Unix，那么您的zll有一项单调的任务，即将所有反斜杠切换为斜杠。

当我们讨论路径的主题时，请记住，map文件中的路径通常与系统的根目录相关：UNIX中的斜杠（_aij/_ a i）或Windows中的某些驱动器号（_aijc:_ a i）。这是正确的，除非特别要求输入URL或引用URL。使用HTML模板文件时，路径是相对于Web服务器的根目录。也就是说，“/tutorial/“是相对于“https://demo.mapserver.org/“的。请阅读http://www.alistaparate.com/articles/slashforward/了解有关URL的一些细节。

Executable

可执行文件

另一个问题是，Unix可执行文件不需要.exe或.com扩展名，但在Windows中需要。如果您使用的是Windows，请将.exe附加到所有实例中的”/cgi bin/mapserv“或”/cgi-bin/mapserv“改为"cgi-bin/mapserv.exe"或"/cgi-bin/mapserv50.exe "。

Other Resources 其他资源
还有其他文档可以让您更好地了解MapServer提供的许多定制。请访问MapServer文档页面：http://www.mapserver.org/documentation.html。在这里，您可以找到几个howto文档，从入门到使用mapscript，这是一个针对mapserver的脚本接口。

Section 1: Static Maps and the MapFile

• 拿个shapefile，任何人我们可以用鼠标在一个浏览器上显示该shapefile形状文件。看：

– Example 1.1 - A map with a single layer：http://localhost/tutorial/example1-1.html

mapserver可以创建一个地图并将其转储到本地目录，或者直接发送到请求的Web浏览器，如本例所示。您可以在不需要HTML页面的情况下查看它，只需输入以下URL:http://<insert hostname or ip address here>/cgi bin/mapserv.exe？map=/ms4w/apps/tutorial/htdocs/example1-1.map&amp;layer=states&amp;mode=map（记住将“<insert hostname or ip address here>”替换为Web服务器的名称，例如“localhost”，或其IP地址，例如“127.0.0.1”）。

这个URL可以分为三部分：第一部分，http://<insert hostname or ip address here>/cgi bin/mapserv.exe？，调用mapserver cgi程序。如果您按原样调用它，您将得到这个熟悉的消息：

No query information to decode. QUERY_STRING is set, but empty.

接下来的三个部分是组成查询字符串的部分。查询字符串包含CGI参数（变量及其值），每个参数由一个与（&amp;）分隔。因此，查看查询字符串，第一个参数“map”有一个值“/ms4w/apps/tutorial/htdocs/example1-1.map”--这告诉mapserver cgi程序（mapserv或mapserv.exe）要处理/解析什么mapfile。下一个参数“layer=states”告诉mapserv.exe“打开”状态层——回想一下，我们将层对象命名为“states”。最后一个参数“mode=map”告诉mapserv.exe如何处理来自mapfile的输出。在本例中，它告诉mapserv.exe直接将映像转储到Web浏览器（客户端），而不首先在服务器上创建临时映像。mapserver“模式”cgi变量可以采用“map”以外的值。例如，如果使用“mode=browse”，mapserver将把映像转储到服务器上的临时目录。浏览模式现在不起作用，但稍后我们将再次使用。

这是map文件的外观（例如1-1.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG
  EXTENT         -97.238976 41.619778 -82.122902 49.385620
  SIZE
  SHAPEPATH      "../data"
  IMAGECOLOR       
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME       "The Upper Great Lakes States"
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
        OUTLINECOLOR
      END
    END
  END # States polygon layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...

mapfile是mapserver的基本配置机制。它由“对象”组成，每个对象可以有关键字或其他对象。它有一个层次结构，一些对象落在其他对象之下…在这个层次结构的顶部是映射对象，所有其他对象都属于它。这个例子显示了对象的一个非常直接的继承关系。当您通过每个示例时，这些层次树的复杂性将增加。

关于mapfiles的一些简短说明：我们用对象名定义mapfile中的每个对象，并用“end”关闭它，在注释前面加上一个磅（）符号。

让我们按对象分解“example1-1.map”。其结构如下：

让我们看下Map文件中的关键字：

MAP地图
每个MAP地图文件都以MAP开始——整个地图文件就是MAP地图对象。

IMAGETYPE图像类型
关键字imagetype用于定义mapserver cgi程序应用于输出的图像格式。在本例中，我们使用索引颜色png（类似于gif）。如果我们使用gif支持、wbmp或jpeg编译gd库，这可能是gif。我们还可以指定其他输出选项（pdf、swf、geotiff），前提是我们编译了对它们的支持并使用outputformat对象指定它们。输出格式超出了本教程的范围，但您可以通过阅读MapServer网站中的文档了解更多信息。

EXTENT范围
此参数指定地图的输出范围——初始地图的边界框。范围值按以下格式给出：<lower left x><lower left y><upper right x><upper right y>，每个值之间用空格分隔。这需要与数据使用相同的单位，或者，如果指定了不同的输出投影，则需要与输出投影使用相同的单位。

在这个例子中，我们的数据是地理投影的，所以单位是十进制的。您可以使用作为gdal/ogr库包一部分的实用程序“ogrinfo”来获取特定形状文件（或其他支持的矢量格式）的范围。下面是我用于获取此示例范围的命令：

ogrinfo -al -so states_ugl.shp

这将返回以下输出：

INFO: Open of `states_ugl.shp'
using driver `ESRI Shapefile' successful.
 
Layer name: states_ugl
Geometry: Polygon
Feature Count:
Extent: (-97.238976, 41.619778) - (-82.122902, 49.385620)
Layer SRS WKT:
(unknown)
AREA: Real (12.3)
PERIMETER: Real (12.3)
STATESP020: Real (11.0)
STATE: String (20.0)
STATE_FIPS: String (2.0)
CLASS: String (5.0)

您还可以使用ArcView或其他开源的GIS包——Quantum GIS、Thuban等。
请随意更改范围的值，以便更好地了解它如何更改您的地图。

SIZE 尺寸
这是MapServer将生成的图像（地图）的大小（像素）。所以我们的地图是400像素宽，300像素高。再次，把它改为你喜欢的内容，看看它是如何影响你的地图的。

SHAPEPATH 形状路径
这是到数据层的路径。您可以提供绝对路径（即“/ms4w/apps/tutorial/data”或“c:/ms4w/apps/tutorial/data”）或相对于map地图文件位置的路径（在本例中，您将使用“../data”）。此路径不必是可访问Web的，除非您希望任何人下载您的原始数据，否则可能不应该是。它与Web没有直接关系，因此在这里甚至不要考虑URL——只需确保运行Web服务器的用户（通常是*nix世界中的“nobody”或“apache”）可以读取shapepath中的数据。

IMAGECOLOR 图像颜色
这是地图的背景色。这些值是RGB值，因此255红色、255绿色和255b会产生白色背景。继续玩这个value。

现在让我们看看图层对象参数：

Layer图层
标记地图对象中图层的开始。尽管默认情况下限制为100，但可以指定任意多个层。要更改此限制，必须编辑map.h头文件（在soure树中）并重新编译mapserver。

NAME名字
这是层标识符。MapServer使用此名称打开和关闭图层。在本例中，它不起作用，因为我们将图层状态STATUS属性设置为默认。在后面的例子中我们将回到这个问题。

DATA数据
数据的名称（本例中为shapefile）。请阅读MapServer矢量数据指南以了解有关如何访问MapServer中的矢量数据的更多信息。

MAPServer通过使用ogr库（gdal软件包的一部分）支持ESRI的shapefile以外的矢量数据格式。请访问gdal项目网站http://www.gdal.org/并阅读http://www.gdal.org/ogr/ogr_formats.html，了解有关各种支持的ogr格式的更多信息。

TYPE类型
它是什么类型的数据？如果是矢量数据，则可以指定它是多边形、直线（即使数据在技术上是多段线，也可以使用直线）还是点。也可以指定光栅或注释数据。这里我们要显示多边形。

STATUS状态
层根据其状态打开或关闭。DEFAULT默认值始终为“开”。当层名称作为查询字符串的一部分传递时，打开或关闭工作。

让我们看看CLASS类对象参数：

CLASS类
标记Layer层对象中CLASS类对象的开头。您可以在一个层中指定任意多个类，尽管默认情况下限制为50个类。您必须重新编译mapserver才能更改此默认值。

NAME名字
此类的描述性标识符。图层对象可以有多个类，就像地图对象可以有多个图层一样。MapServer将类名用作图例的标签，因此在命名类时请确保使用适当的描述性名称。我们稍后将在本教程中讨论图例。

最后，我们来看一下STYLE样式对象参数：

STYLE风格
标记样式对象的开始。您可以在一个类中定义多个样式——当您想将一个样式覆盖到另一个样式上时，这很有用。

COLOR颜色
这是多边形的填充颜色。如果类型是line，这是line颜色。这些值采用RGB格式。

OUTLINECOLOR轮廓颜色
这是多边形的轮廓颜色。这些值采用RGB格式。默认情况下，MapServer不绘制多边形轮廓，因此如果要查看多边形边界，则需要定义一个大纲颜色。

这结束了本教程中的第一个示例。建议您更改映射文件中关键字的值。它将帮助您理解这些关键字的作用。

Example 1.2: Static Map with Two Layers

• 我们可以重复显示相同的shapefile数据集。我们可以在一个图层中显示多边形属性，在另一个图层中显示线条属性。˘

– Example 1.2 - A map with two layers

http://localhost/cgi-bin/mapserv.exe?map=/ms4w/apps/tutorial/htdocs/example1-2.map&layer=states_poly&layer=states_line&mode=map

与第一个示例一样，此图像是通过将<img>标记的源链接到此URL生成的。这就是本节中大多数示例的工作方式。

无论如何，您会注意到这里的地图与第一个示例相同。是的，但地图文件不同。看看。

这是映射文件的外观（example 1-2.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG
  EXTENT         -97.238976 41.619778 -82.122902 49.385620
  SIZE
  SHAPEPATH      "../data"
  IMAGECOLOR       
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states_poly
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME       "States"
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
      END
    END
  END # States polygon layer ends here
 
  LAYER # States line layer begins here
    NAME         states_line
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    CLASS
      NAME       "State Boundary"
      STYLE
        COLOR
      END
    END
  END # States line layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...

按对象划分的map文件结构如下所示：

在这里，我们将原始层分为两层。第一层仍然是多边形层，但样式不再具有outline颜色。第二层与第一层类似，只是类型更改为线条，样式中的颜色更改为与第一个示例中的outline轮廓颜色相同的颜色。这将生成与第一个图像相同的图像…那么，为什么要这样做？如果我们继续在状态层的顶部添加层，那么轮廓很可能会被其他层覆盖。为了在添加这些其他层之后仍能看到状态边界，我们必须将状态边界线层与状态多边形层分离，并将其放在其他层的顶部。我们如何定义/添加层是有顺序的，在本节中，您将清楚地看到它。

Example 1.3: Displaying Classes in a Layer
• 我们可以选择要显示的形状文件的哪些部分。我们使用类对象来完成这项工作…
– 示例1.3-使用类制作“有用”地图

这是map地图文件的外观（Example 1-3.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG
  EXTENT         -97.238976 41.619778 -82.122902 49.385620
  SIZE
  SHAPEPATH      "../data"
  IMAGECOLOR       
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states_poly
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME 'States'
      EXPRESSION 'land' # Only polygons where "CLASS" = 'land' will be drawn.
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
      END
    END
    CLASS
      NAME 'Water'
      EXPRESSION 'water' # Only polygons where "CLASS" = 'water' will be drawn.
      STYLE
        COLOR
      END
    END
  END # States polygon layer ends here
 
  LAYER # States line layer begins here
    NAME         states_line
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        COLOR
      END
    END
  END # States line layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...

按对象划分的map文件结构如下所示：

我们的地图文件仍然只有两个图层，但是多边形图层被分解为两个类。让我们看看其他参数：

CLASSITEM

此关键字用于指定用于分隔类对象的属性。在这个例子中，属性是“class”。如果打开与该层的shapefile关联的数据库文件，您将看到有一个名为“class”的列（属性）。

我们如何知道要使用哪个属性？好吧，shapefiles中的数据库记录存储在dbf文件中。您可以在电子表格程序（如openoffice.org的calc）或桌面地理信息系统软件（如qgis、thuban或arcview）中打开它。如果您的数据带有元数据（应该是！），您可以浏览该元数据文件以获取属性信息。您还可以使用“ogrinfo”在shapefiles中显示基本属性信息——回顾示例1.1（在“layer srs wkt：”后面的最后几行显示属性名称和类型）。

EXPRESSION

对于每个类，我们指定要使用的属性值。这是最简单的表达形式。表达式可能比这更复杂，允许计算正则表达式或逻辑表达式。请查看mapfile引用页，了解如何使用表达式。

Example 1.4: Labeling the Map

我们也可以在地图上添加标签…

MapServer有一个非常灵活的标签引擎。它支持本机位图和TrueType字体。TrueType支持字体缩放。标签的角度和位置可以定制…如果您花时间学习创建好标签所涉及的许多参数，您将获得信息丰富、美观的地图。

这是map文件的外观（例如1-4.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG
  EXTENT         -97.238976 41.619778 -82.122902 49.385620
  SIZE
  SHAPEPATH      "../data"
  IMAGECOLOR
  FONTSET        "../fonts/fonts.list"
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states_poly
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    # Just like CLASSITEM, LABELITEM defines the database attribute that you
    # will be using to draw labels.  In this case, the values of the attribute
    # "STATE" will be used to label the states polygons.
    LABELITEM    "STATE"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME 'States'
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
      END
 
      # There can be labels in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple labels in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      # MapServer has a very flexible labeling system.  With that flexibility
      # comes complexity, specially when using truetype fonts.  Please read
      # through the LABEL section of the MapServer map file documentation at
      # http://www.mapserver.org/mapfile for more information.
      LABEL
        COLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END
 
    CLASS
      NAME 'Water'
      EXPRESSION 'water'
 
      STYLE
        COLOR
      END
    END
  END # States polygon layer ends here
 
  LAYER # States line layer begins here
    NAME         states_line
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    CLASSITEM    "CLASS"
    CLASS
      NAME 'State Boundary'
      EXPRESSION 'land'
      STYLE
        COLOR
      END
    END
  END # States line layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...

按对象划分的map文件结构如下所示：

这里我们介绍LABEL对象的几个参数：

FONTSET字体集
这里我们指定TrueType字体列表（或字体集）文件的完整路径。此文件列出了每个可用字体。有关详细信息，请参见文件本身和mapfile引用。fontset是地图对象的参数。

LABELITEM
这将指定要用于标记的数据属性，在本例中为“STATE”。labelitem是层对象的参数。

LABEL标签
标记标签对象的开头。标签对象可用于其他对象（即scaleBar对象）下。

COLOR颜色
在标签对象中，颜色指定标签文本的颜色。

SHADOWCOLOR阴影颜色
指定标签文本的阴影颜色。

SHADOWSIZE阴影大小
指定阴影大小。该值对应于x和y以像素为单位移动。所以，“2 2”是指两个像素宽两个像素高。

TYPE类型
在Label对象中，TYPE指定要使用的字体类型。我们可以选择TrueType或BitMap（内置字体）。我们选择TrueType。

FONT字体
如果将TYPE指定为TrueType，则需要指定要使用的字体。这里的值是字体列表文件中的“别名”。

SIZE尺寸
如果使用TrueType字体，则值为像素大小。如果是位图，可以说“小”或“大”。

ANTIALIAS
这将打开或关闭TrueType抗锯齿。请记住，值不是开或关，而是真或假。

POSITION位置
标签文本相对于标签点的位置。该值是垂直和水平位置的组合。垂直对齐有以下选项：C代表中心，U代表上部，L代表下部。对于水平对齐，您有以下选项：C代表中心，L代表左侧，R代表右侧。因此，要将标签文本与标签ID的中心对齐，需要使用值“cc”（中心）。或者如果你想把它放在身份证的左下角，你可以用LL。另一种方法是让MapServer决定标签的最佳位置。为此，您将使用值“auto”。

PARTIALS部分
告诉MapServer是否生成不完整的标签文本。这里的默认设置是不生成标签文本的片段。该值为真或假。

MINDISTANCE最小距离
这是重复标签之间的最小距离（像素）。看看如果增加或减少这个值会发生什么。

BUFFER缓冲器
每个标签的填充（像素）。这用于增强可读性。4个像素的缓冲区意味着在4个像素的范围内不会绘制任何标签。再次，改变看看它是如何工作的。

还可以创建与多边形层分离的标签。对ANNOTATION数据类型执行此操作。查看下一个示例的映射文件，了解如何实现这种标记。您将注意到“label”层中的类对象的颜色参数值为“-1-1-1”。负数告诉MapServer给这个类一个透明的颜色（标签ID不显示）。再次，使用这些值了解它如何影响地图。

 Example 1.5: Adding a Raster Layer

除了支持矢量数据（点、线、多边形和注释），MapServer还可以显示光栅数据。通过使用gdal库，mapserver可以输入和输出多种光栅格式。在4.x之前的版本中，光栅输入仅限于单层、灰度或索引彩色图像，而MapServer现在支持RGB和多光谱（多层）图像。此示例演示如何选择使用多光谱数据时要显示的图层。在使用RGB和多光谱图像时，可能会出现明显的性能问题。

因为MapServer5.x使用gd版本2.0.x库来生成输出图像，所以它也支持RGB（24位或真彩色）输出。因此，除了8位（索引颜色或灰度）PNG，您现在还可以使用PNG24（真颜色）进行输出。此示例使用PNG24作为ImageType。与RGB输入一样，使用PNG24时可能会出现明显的性能问题。

mapserver实际上也可以使用gdal生成输出图像，但这是另一个主题。如果您想了解更多信息，请查看mapfile引用中的outputformat对象。

这是映射文件的外观（例如1-5.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG24
  EXTENT         -97.238976 41.619778 -82.122902 49.385620
  SIZE
  SHAPEPATH      "../data"
  IMAGECOLOR
  FONTSET        "../fonts/fonts.list"
  SYMBOLSET      "../symbols/symbols35.sym"
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
  #
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME 'States'
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
      END
    END
  END # States polygon layer ends here
 
  # In addition to vector data (shapefiles are vector data), MapServer supports
  # a host of raster formats.  In GIS world, one of the most common raster
  # formats is GeoTIFF, a TIFF image with geospatial headers.  MapServer also
  # supports JPEG, PNG, GIF, and other common formats.  Other raster formats
  # supported by MapServer include ESRI Arc/Info grid, HDF and HDF-EOS, NetCDF,
  # Generic raster binaries, OGC Web Map Service (WMS) layers, etc.  Pretty much
  # any raster format you can think of is probably supported, thanks to the
  # impressive Geospatial Data Abstraction Library (GDAL, pronounced "GOODALL"
  # or GOODLE?).  More information on GDAL is available at http://www.gdal.org.
  #
  # MapServer .x can read and display bitmapped (like GIFs), RGB/A (true
  # color), and multispectral (images with more than  bands, like raw LandSat
  # images) rasters.
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_8bit.tif"
    STATUS       OFF
    TYPE         RASTER
    PROCESSING   "BANDS=1,2,3"
    OFFSITE
  END # MODIS raster layer ends here
 
  LAYER # States line layer begins here
    NAME         states_line
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  # Labels can be defined in its own layer.  This is useful if, say, you want
  # to label a polygon layer that's covered by another layer.  By keeping the
  # label separate from the polygon and placing it near the bottom of the map
  # file (so its drawn on, or near the, top), you can still see the label even
  # though you might not be able to see the polygon.  It is also a good
  # alternate to point symbols.
  #
  # A label layer is actually defined with ANNOTATION type (This is derived from
  # points, Node IDs for lines, or polygon IDs).
  LAYER # States label layer begins here
    NAME         states_label
    DATA         states_ugl
    STATUS       OFF
    TYPE         ANNOTATION
 
    CLASSITEM    "CLASS"
 
    # Just like CLASSITEM, LABELITEM defines the database attribute that you
    # will be using to draw labels.  In this case, the values of the attribute
    # "STATE" will be used to label the states polygons.
    LABELITEM    "STATE"
 
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
 
      # There can be labels in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple labels in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      # MapServer has a very flexible labeling system.  With that flexibility
      # comes complexity, specially when using truetype fonts.  Please read
      # through the LABEL section of the MapServer map file documentation at
      # http://www.mapserver.org/mapfile for more information.
      LABEL
        COLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...

按对象划分的map地图文件结构如下所示：

当您查看map地图文件时，您将看到新的图层对象被添加到区域polygon多边形图层的下面（后面）。为什么？mapserver以相反的顺序显示层——后进先出（lifo）。地图文件中定义的第一个图层绘制在地图的底部。

所以，如果我们画了state多边形层，它会在底部。因为光栅图层被绘制在上面，所以我们看不到它。这就是为什么第一层的状态值为off的原因。状态线图层定义在光栅图层的下方，以便在顶部绘制（您可以看到）。这就是我们将状态线层与状态多边形层分离的原因。当然，标签是在最上面。

MapServer可以根据其他图层的状态自动打开或关闭图层——比如说，当光栅图层打开时，希望关闭状态多边形图层。这是通过使用Requires参数来完成的。记住这一点，因为一旦开始创建自己的MapServer应用程序，您可能会想要使用它。

让我们看看mapfile中引入的新参数：

IMAGETYPE 图像类型
这不是新的，但值“png24”是。PNG24是PNG格式的24位或真彩色版本。mapserver现在拥有数百万个颜色组合，而不是仅限于输出图像的256种颜色组合。顺便说一下，试着把这个值改回png。请注意，使用这两种格式生成图像所需的时间。在选择真彩色和索引颜色时，要考虑生成图像所需的时间。

SYMBOLSET符号集
指向符号定义文件的路径。此文件中的符号由类对象中的符号参数引用。现在不需要，但我想我现在就把它扔到这里。更多信息，请参考地图文件参考和地图服务器的地图符号构造。

DATA数据“光栅/mod09a1203161_ugl_ll_8bit.tif”
在新添加的图层对象中，数据参数指向geotiff图像。与矢量数据集一样，MapServer支持多种光栅文件格式。这种支持是通过使用gdal库来实现的。有关MapServer支持的不同光栅格式的详细信息，以及有关在MapServer中使用光栅的一般性讨论，请阅读http://www.mapserver.org/input/graster.html上的光栅数据操作方法。

TYPE RASTER类型光栅
当使用光栅数据（图像）时，我们使用值光栅作为参数类型，而不是矢量数据的多边形、直线和点值以及标签ID的注释。

PROCESSING "BANDS=1,2,3"处理“波段=1,2,3”
在MapServer 4.x中，这个层对象参数是新的。处理关键字有很多值，但在本例中，我们使用它来选择要显示多光谱图像中的波段。这里的值是将传递到gdal库的字符串。有关这一点的文档目前是最少的，但有关使用processing关键字的更多示例，请参阅mapfile参考。

OFFSITE
此参数告诉MapServer要渲染为背景（或忽略）的像素值。您可以使用图像处理或图像操作程序（例如，Imagine、Photoshop、Gimp）获取像素值。

要在使用RGB图像而不是索引颜色图像时比较地图创建速度，请替换地图文件中的以下行：

DATA "raster/mod09a12003161_ugl_ll_8bit.tif"
STATUS DEFAULT
TYPE RASTER
PROCESSING "BANDS=1,2,3"
OFFSITE   

为：

DATA "raster/mod09a12003161_ugl_ll_idxa.tif"
STATUS DEFAULT
TYPE RASTER
OFFSITE   

另外，尝试将imagetype从png24更改为png。

Example 1.6: Defining Projections and Extents

我们可以将我们的数据从几乎任何投影重新投影到几乎任何…是的，看看！

哇！这里发生了什么？

你刚刚经历了一次on-the-fly的再投射。在map文件中定义投影对象时，MapServer将图层和投影信息传递给执行重投影的proj.4库。有关proj.4库的更多信息，请访问http://trac.osgeo.org/proj/。

这个例子试图为MapServer中的投影支持提供一些帮助。

这是map文件的外观（例如1-6.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG24
  # EXTENT 199949.651166 -371954.772084 1472121.6862 632767.19157
  EXTENT       201621.496941 -294488.285333 1425518.020722 498254.511514 # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  #
  # This is the output PROJECTION definition ------
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
      "proj=laea"
      "ellps=clrk66"
      "lat_0=45"
      "lon_0=-100"
 
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    #
    # "init=epsg:2163"
  END # End of the output Projection definition ---
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
  #
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum.
    #
    # PROJECTION objects within the LAYER object define the input
    # projection--this is the native projection of your data.
    PROJECTION
      "init=epsg:4326"
    END
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME 'States'
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
      END
    END
  END # States polygon layer ends here
 
  # In addition to vector data (shapefiles are vector data), MapServer supports
  # a host of raster formats.  In GIS world, one of the most common raster
  # formats is GeoTIFF, a TIFF image with geospatial headers.  MapServer also
  # supports JPEG, PNG, GIF, and other common formats.  Other raster formats
  # supported by MapServer include ESRI Arc/Info grid, HDF and HDF-EOS, NetCDF,
  # Generic raster binaries, OGC Web Map Service (WMS) layers, etc.  Pretty much
  # any raster format you can think of is probably supported, thanks to the
  # impressive Geospatial Data Abstraction Library (GDAL, pronounced "GOODALL"
  # or GOODLE?).  More information on GDAL is available at http://www.gdal.org.
  #
  # MapServer .x can read and display bitmapped (like GIFs), RGB/A (true
  # color), and multispectral (images with more than  bands, like raw LandSat
  # images) rasters.
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_8bit.tif"
    STATUS       OFF
    TYPE         RASTER
    PROCESSING   "BANDS=1,2,3"
    OFFSITE        
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  LAYER # States label layer begins here
    NAME         states_label
    DATA         states_ugl
    STATUS       OFF
    TYPE         ANNOTATION
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
 
    # Just like CLASSITEM, LABELITEM defines the database attribute that you
    # will be using to draw labels.  In this case, the values of the attribute
    # "STATE" will be used to label the states polygons.
    LABELITEM    "STATE"
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
 
      # There can be labels in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple labels in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      # MapServer has a very flexible labeling system.  With that flexibility
      # comes complexity, specially when using truetype fonts.  Please read
      # through the LABEL section of the MapServer map file documentation at
      # http://www.mapserver.org/mapfile for more information.
      LABEL
        COLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...

在我们的地图文件中，您可能注意到的第一件事是原始范围已被注释掉，新的范围值看起来与纬度和经度值不同。另外，我们在顶部附近和每个Layer层中添加了一个投影对象。

让我们看看新的对象和参数：

EXTENT 201621.496941 -294488.285333 1425518.020722 498254.511514

我们提供给MapServer的范围需要与输出投影使用相同的单位。由于兰伯特方位角的等面积单位是米，我们必须给新的范围以米。我们可以使用arcview或其他一些gis包计算新的范围，也可以使用proj.4的cs2cs实用程序。下面的命令可用于重新投影原始范围值：

cs2cs +proj=latlong +datum=WGS84 +to +proj=laea +ellps=clrk66 +lat_0=45 +lon_0=-100

键入命令后，输入西南坐标对（左下角坐标），用空格分隔：-97.5 41.619778
“cs2cs”实用程序给出的值：

          208398.01       -372335.44 0.000

然后键入东北坐标对（右上角坐标），再次用空格分隔：-82.122902 49.38562，并返回以下值：

            1285308.08      632638.93 0.000

您会注意到“cs2cs”返回一组三个值。您可以忽略第三个值0.000，因为它表示高度（我们不使用）。无论如何，我们不能将范围表示为：

            EXTENT 208398.01 -372335.44 1285308.08 632638.93

但这与上面的范围不符，你说。好吧，这就是你回绝的时候通常会发生的事情——地图不一定像你想象的那样居中。你可以绕着它转，向左走几千米，向右再加几米。或者，您可以使用图形化的地理信息系统包来提供范围。以下是使用ArcView获取范围的说明。

MapServer可以通过两种方式获取投影定义。第一个显示在映射文件的输出投影对象（第一个投影块）中。这是将参数传递到proj.4库的传统方法。另一种方法是使用EPSG代码。这些代码是欧洲石油调查集团（EPSG）定义的标准投影代码（或空间参考标识符）。在我们的兰伯特方位角等面积投影，它有一个代码“2163”。如果在投影后注释掉这四行，并取消对行“init=epsg:2163”的注释，这将向项目4提供相同的信息。如果您想了解EPSG代码的更多信息，请查看“/usr/local/share/proj/epsg”或“c:/proj/nad/epsg”（MS4W中的“/ms4W/proj/nad”）。此外，请访问EPSG网站http://www.epsg.org。

如果您需要了解有关投影的更多信息，请查看以下链接：

http://www.colorado.edu/geography/gcraft/notes/mapproj/mapproj_f.html
http://www.geography.hunter.cuny.edu/mp/
http://www.nationalatlas.gov/articles/mapping/a_projections.html
http://en.wikipedia.org/wiki/Map_projection
http://erg.usgs.gov/isb/pubs/MapProjections/projections.html

你可以通过在网上搜索“地图投影”找到更多信息。

 Example 1.7: Adding OGC WMS Layers

我们可以使用来自互联网上其他地图服务器的层（只要它们是WMS服务器）。

MapServer的另一个令人兴奋的特性是它能够使用来自其他地图服务器的层。在这种情况下，MapServer应用程序将成为WMS（或WFS）客户机。mapserver还可以将map文件中的层共享（或服务于其他地图服务器）。这使应用程序成为一个WMS（或WFS）服务器。什么是WMS或WFS？这些是由开放地理空间联盟（OGC）发布的“基于Web的互操作性服务”规范。

wms代表web map服务，wfs代表web feature服务。简单来说，这两种规范的区别在于，WMS使用Web光栅格式（PNG、GIF、JPEG）共享层，而WFS使用地理标记语言GML。第三个OGC互操作性规范是Web Coverage Services规范或WCS——MapServer仅在服务器级别支持此规范。要查找有关WMS、WFS和WCS的更多信息，请访问OGC的网站，并查找OGC实现规范或OGC抽象规范。MapServer网站还提供了这些规范的文档。

此示例演示如何在map地图文件中添加WMS层。

这是map文件的外观（示例1-7.map）：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG24
  EXTENT        201621.496941 -294488.285333 1425518.020722 498254.511514 # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  #
  # This is the output PROJECTION definition ------
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
    #  "proj=laea"
    #  "ellps=clrk66"
    #  "lat_0=45"
    #  "lon_0=-100"
    #
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    "init=epsg:2163"
 END
 
  # The web object is defined at the level below the map object.  All
  # web-related parameters (I interchange "parameters" and "keyword/value
  # pairs" quite frequently, sorry about that) are defined in this object.
  WEB
    IMAGEPATH "/ms4w/tmp/"
    IMAGEURL  "/tmp/"
  END
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
  #
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum.
    #
    # PROJECTION objects within the LAYER object define the input
    # projection--this is the native projection of your data.
    PROJECTION
      "init=epsg:4326"
    END
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it's
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME 'States'
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR
      END
    END
  END # States polygon layer ends here
 
  # In addition to vector data (shapefiles are vector data), MapServer supports
  # a host of raster formats.  In GIS world, one of the most common raster
  # formats is GeoTIFF, a TIFF image with geospatial headers.  MapServer also
  # supports JPEG, PNG, GIF, and other common formats.  Other raster formats
  # supported by MapServer include ESRI Arc/Info grid, HDF and HDF-EOS, NetCDF,
  # Generic raster binaries, OGC Web Map Service (WMS) layers, etc.  Pretty much
  # any raster format you can think of is probably supported, thanks to the
  # impressive Geospatial Data Abstraction Library (GDAL, pronounced "GOODALL"
  # or GOODLE?).  More information on GDAL is available at http://www.gdal.org.
  #
  # MapServer .x can read and display bitmapped (like GIFs), RGB/A (true
  # color), and multispectral (images with more than  bands, like raw LandSat
  # images) rasters.
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_8bit.tif"
    STATUS       OFF
    TYPE         RASTER
    PROCESSING   "BANDS=1,2,3"
    OFFSITE        
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  # MapServer can consume (in ESRI parlance) layers from other map servers as
  # long as those servers are Web Mapping Service (WMS) providers.  WMS is a
  # web service specification from Open Geospatial Consortium (OGC) and is
  # intended to be an interoperability standard for web mapping applications.
  # This allows us to display layers we don't usually have (or can't store in
  # our computers due to space limitations).  The downside is that we have to
  # depend on some other server to display our layer, and that server can be
  # down when you really need it.  The cool thing is that JPL has a WMS server
  # that serves out MODIS and LandSat maps for the whole world--try storing
  # those datasets on your computer!
  LAYER # MODIS WMS map from JPL
    NAME         modis_jpl
    TYPE         RASTER
    OFFSITE
    STATUS       OFF
    CONNECTIONTYPE WMS
    CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
 
    METADATA
      "wms_srs" "EPSG:4326"
      "wms_name" "modis"
      "wms_server_version" "1.1.1"
      "wms_format" "image/jpeg"
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # Modis WMS image ends here
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  LAYER # States label layer begins here
    NAME         states_label
    DATA         states_ugl
    STATUS       OFF
    TYPE         ANNOTATION
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
 
    # Just like CLASSITEM, LABELITEM defines the database attribute that you
    # will be using to draw labels.  In this case, the values of the attribute
    # "STATE" will be used to label the states polygons.
    LABELITEM    "STATE"
 
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
 
      # There can be labels in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple labels in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      # MapServer has a very flexible labeling system.  With that flexibility
      # comes complexity, specially when using truetype fonts.  Please read
      # through the LABEL section of the MapServer map file documentation at
      # http://www.mapserver.org/mapfile for more information.
      LABEL
        COLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # end of map file

让我们来看看WMS层：

LAYER #来自JPL的MODIS WMS地图
标记WMS Layer图层对象的开始。

NAME modis_jpl
The LAYER 标识符.

TYPE RASTER 类型光栅
因为这个WMS层是一个图像，所以我们使用光栅作为层类型。

OFFSITE 0 0 0
Ignore the black background color忽略黑背景色

STATUS OFF
Turn this layer off by default.默认关掉图层

CONNECTIONTYPE WMS WMS连接类型
要使用的层连接类型。默认值是本地的——如果我们想显式定义，我们将向地图文件中的所有其他向量和光栅层添加CONNECTIONTYPE LOCAL 。相反，我们只定义外部的连接类型。WMS是一个外部数据层，来自另一个地图服务器。

连接“http://mapus.jpl.nasa.gov/wms.cgi？”
允许我们从另一个服务器“获取”数据的连接字符串。对于WMS连接，这是一个URL。如果我们使用PostGIS数据库，它将是一个SQL语句。请注意，字符串必须在映射文件中的一行中。

METADATA 元数据
标记WMS层的元数据对象的开头。MapServer使用此对象中定义的参数以及上面的连接参数来形成对WMS服务器的有效WMS请求。

"wms_srs" "epsg:4326"
WMS投影。有时，WMS服务器支持多个投影。如果是这种情况，您可能希望在输出投影中请求映射。不幸的是，JPL服务器不支持这种投影。

"wms_name" "modis"
WMS层名称。这就像添加参数“layers=modis”。

"wms_server_version" "1.1.1"
服务器符合的WMS版本。MapServer遵循1.1.1版。

"wms_format" "image/jpeg"
T我们期望从WMS服务器接收的图像格式。您可以尝试将该值替换为“image/png”或其他内容。

END
标记METADATA元数据对象的结尾

要了解有关向应用程序添加WMS层的更多信息，请访问WMS客户端操作说明文档。

除了添加WMS图层对象，地图下还有一个新对象。这是Web对象。Web对象中有两个参数：

imagepath'/data/tmp/'
指向Web可访问临时目录的绝对本地路径。运行Web服务器进程的用户应该能够写入此目录。确保路径末尾包含斜线（/）。（您的IMAGEPATH可能如下所示：“/home/apache/htdocs/tmp/”或“c:/inetpub/wwwroot/tmp/”。

IMAGEURL '/tmp/'
这是相对于Web服务器的根目录显示ImagePath的方式。如果必须为此键入完整的URL，它将是“http://terrasip.gis.umn.edu/tmp/”。确保路径末尾包含斜线（/）。

最后，在MAP对象中，我添加了一个新参数：NAME。这是MAP对象的标识符。MapServer将此作为它创建的所有图像的前缀，并将其转储到“tmp”目录。在这一点上不需要它，但是拥有它也不会带来伤害。

如果要将数据层共享到其他地图服务器，则需要在地图对象内以及要共享的每个图层对象内添加元数据对象。从另一台服务器添加的所有WMS层将自动层叠，并且也将对其他服务器可用。要了解有关如何使MapServer应用程序成为WMS服务器的更多信息，请阅读WMS服务器操作说明文档。还存在用于配置MapServer应用程序以支持WFS标准的文档，无论是作为WFS服务器还是作为WFS客户机。

Example 1.8: Changing the Map's Output Format

MapServer可以输出各种格式，如PDF和geotiff。

根据您选择的格式，图像可能不会显示在浏览器上。如果链接无法显示在浏览器上，请右键单击上面的图形，并将链接保存为您在地图文件中指定的任何格式。

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  NAME           EX1.8_
  EXTENT         201621.496941 -294488.285333 1425518.020722 498254.511514 # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  IMAGECOLOR
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  IMAGETYPE PNG24
 
  OUTPUTFORMAT
    NAME png
    DRIVER "GD/PNG"
    MIMETYPE "image/png"
    IMAGEMODE PC256
    EXTENSION "png"
  END
  OUTPUTFORMAT
    NAME png24
    DRIVER "GD/PNG"
    MIMETYPE "image/png"
    IMAGEMODE RGBA
    EXTENSION "png"
  END
  OUTPUTFORMAT
    NAME jpeg
    DRIVER "GD/JPEG"
    FORMATOPTION "QUALITY=75"
    MIMETYPE "image/jpeg"
    IMAGEMODE RGB
    EXTENSION "jpg"
  END
  OUTPUTFORMAT
    NAME GTiff
    DRIVER "GDAL/GTiff"
    MIMETYPE "image/tiff"
    IMAGEMODE RGB
    EXTENSION "tif"
  END
  #OUTPUTFORMAT
  #  NAME pdf
  #  MIMETYPE "application/x-pdf"
  #  DRIVER pdf
  #  #FORMATOPTION "OUTPUT_TYPE=RASTER" # not mandatory but needed for WMS layer
  #END
  OUTPUTFORMAT
    NAME AGG
    DRIVER "AGG/PNG"
    IMAGEMODE RGB
  END
  OUTPUTFORMAT
    NAME AGGA
    DRIVER "AGG/PNG"
    IMAGEMODE RGBA
  END
  OUTPUTFORMAT
    NAME AGGJ
    DRIVER "AGG/JPEG"
    IMAGEMODE RGB
  END
 
  # The web object is defined at the level below the map object.  All
  # web-related parameters (I interchange "parameters" and "keyword/value
  # pairs" quite frequently, sorry about that) are defined in this object.
  WEB
    IMAGEPATH '/ms4w/tmp/ms_tmp/'
    IMAGEURL  '/ms_tmp/'
  END
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  #
  # This is the output PROJECTION definition ------
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
    #  "proj=laea"
    #  "ellps=clrk66"
    #  "lat_0=45"
    #  "lon_0=-100"
    #
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    "init=epsg:2163"
  END
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
  #
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum.
    #
    # PROJECTION objects within the LAYER object define the input
    # projection--this is the native projection of your data.
    PROJECTION
      "init=epsg:4326"
    END
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need but it is good cartographic practice to limit
    # classes to  to  per layer. (There are also limits as with layers and
    # it's senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      EXPRESSION 'land'
      STYLE
        SYMBOL
        COLOR
      END
    END
  END # States polygon layer ends here
 
  # In addition to vector data (shapefiles are vector data), MapServer supports
  # a host of raster formats.  In GIS world, one of the most common raster
  # formats is GeoTIFF, a TIFF image with geospatial headers.  MapServer also
  # supports JPEG, PNG, GIF, and other common formats.  Other raster formats
  # supported by MapServer include ESRI Arc/Info grid, HDF and HDF-EOS, NetCDF,
  # Generic raster binaries, OGC Web Map Service (WMS) layers, etc.  Pretty much
  # any raster format you can think of is probably supported, thanks to the
  # impressive Geospatial Data Abstraction Library (GDAL, pronounced "GOODALL"
  # or GOODLE?).  More information on GDAL is available at http://www.gdal.org.
  #
  # MapServer .x can read and display bitmapped (like GIFs), RGB/A (true
  # color), and multispectral (images with more than  bands, like raw LandSat
  # images) rasters.
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_8bit.tif"
    STATUS       OFF
    TYPE         RASTER
    PROCESSING   "BANDS=1,2,3"
    OFFSITE        
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  LAYER # MODIS WMS map from JPL
    NAME         modis_jpl
    TYPE         RASTER
    OFFSITE
    STATUS       OFF
    CONNECTIONTYPE WMS
    CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
 
    METADATA
      "wms_srs" "EPSG:4326"
      "wms_name" "modis"
      "wms_server_version" "1.1.1"
      "wms_format" "image/jpeg"
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # Modis WMS image ends here
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      EXPRESSION 'land'
      STYLE
        #SYMBOL     'line1'
        COLOR
        #SIZE
      END
    END
  END # States line layer ends here
 
  LAYER # States label layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         ANNOTATION
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    LABELITEM    "STATE"
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
      LABEL
        COLOR
        TYPE     TRUETYPE
        FONT     arial-bold
        SIZE
        ANTIALIAS    TRUE
        POSITION     CL
        PARTIALS     FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # end of map file

我们的mapfile现在包含一个新的对象outputformat。此对象在map对象内定义，并与imagetype关键字一起使用。根据您使用MapServer编译的库，您可以有几个输出格式选择——gd库提供PNG（8位和24位）、GIF、JPEG和WBMP；gdal库是许多MapServer输入格式的源，也可以向PNG、JPEG、TIFF/GEOTIFF和其他RASTE提供输出。R格式；pdflib库提供PDF输出；ming库提供闪存输出。查看outputformat对象并通过更改mapfile上的imagetype关键字进行实验。输出格式的名称应用作imagetype值（例如：imagetype png或imagetype png24）。

请在以下位置查阅outputformat对象引用：
http://www.mapserver.org/mapfile/outputformat.html outputformat

Example 1.9: Interactive Maps and the Browse Mode

上面的地图是在“地图”模式下创建的。这是一个静态地图（单击它不会改变）。

这个动态地图是在“浏览”模式下生成的。点击地图上的任何一点，看看会发生什么。

这两个地图都使用相同的mapfiile文件定义。区别在于第二个地图（动态创建的地图）依赖于HTML表单进行交互。如果你看一下这个页面是如何与前一个页面链接的，你会发现它与前一个例子不一样。用mapserver的术语来说，这个页面就是一个HTML模板。您将在第2部分中了解有关HTML模板的更多信息。

查看此页面中的“表单”块（右键单击浏览器并选择“查看源代码”或类似内容）：

        <!-- START OF MAPSERVER FORM -->
        <form name="mapserv" method="GET" action="/cgi-bin/mapserv.exe">
          <!-- HIDDEN MAPSERVER CGI VARIABLES -->
          <input type="hidden" name="map" value="[map]">
          <input type="hidden" name="imgext" value="[mapext]">
          <input type="hidden" name="imgxy" value="199.5 149.5">
          <input type="hidden" name="zoom" value="">
          <input type="hidden" name="mode" value="browse">
 
          <div align="center">
        <table border="" cellpadding="" cellspacing="">
          <tr>
                <td>
                  <!-- THE INTERACTIVE, DYNAMICALLY CREATED MAP --
                  <input type="image" name="img" src="[img]"
                    width="" height="">
                </td>
              </tr>
            </table>
          </div>
        </form>

每当用户单击地图时，此块执行mapserver cgi程序（“/cgi-bin/mapserv.exe”）。地图实际上是另一种形式的“输入”，在这里用行表示：

<input type="image" name="img" src="[img]" width="400" height="300">

方括号（[map]、[mapext]和[img]）中的项称为mapserver标记——这些是mapserver cgi变量，在重新加载时会被mapserver cgi程序替换。标记[map]是mapfile路径的一个占位符，因此在运行mapserver时，它被替换为“/ms4w/apps/tutorial/htdocs/example1-9.map”。标记[mapext]替换为当前地图范围“91734.994981-533247.003346 1432483.085284 471473.996656”，并且[img]标记替换为mapserver cgi程序创建的图像路径，“/ms_tmp/ex1.9_156222312833540.png”。继续检查映像路径（/ms4w/tmp/）是否存在此映像。（这些参数是在.map文件里获取的吗？：）

值为“browse”的隐藏变量“mode”告诉CGI程序需要在“tmp”目录中创建和转储图像。然后，这个图像被引用为[img]，这就是您在浏览器上看到的。

现在，看看地图文件：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  NAME           EX1.9_
  IMAGETYPE      PNG24
  EXTENT         -   # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  # The web object is defined at the level below the map object.  All
  # web-related parameters (I interchange "parameters" and "keyword/value
  # pairs" quite frequently, sorry about that) are defined in this object.
  WEB
    TEMPLATE  'example1-9.html'
    IMAGEPATH '/ms4w/tmp/ms_tmp/'
    IMAGEURL  '/ms_tmp/'
  END
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  #
  # This is the output PROJECTION definition ------
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
    #  "proj=laea"
    #  "ellps=clrk66"
    #  "lat_0=45"
    #  "lon_0=-100"
    #
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    "init=epsg:2163"
  END
 
  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you'd like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at .  You'd
  # have to have a very specialized application to need more than  layers in
  # your application.
  #
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum.
    #
    # PROJECTION objects within the LAYER object define the input
    # projection--this is the native projection of your data.
    PROJECTION
      "init=epsg:4326"
    END
 
    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"
 
    CLASS
      EXPRESSION 'land'
      STYLE
        SYMBOL
        COLOR
      END
    END
  END # States polygon layer ends here
 
  # In addition to vector data (shapefiles are vector data), MapServer supports
  # a host of raster formats.  In GIS world, one of the most common raster
  # formats is GeoTIFF, a TIFF image with geospatial headers.  MapServer also
  # supports JPEG, PNG, GIF, and other common formats.  Other raster formats
  # supported by MapServer include ESRI Arc/Info grid, HDF and HDF-EOS, NetCDF,
  # Generic raster binaries, OGC Web Map Service (WMS) layers, etc.  Pretty much
  # any raster format you can think of is probably supported, thanks to the
  # impressive Geospatial Data Abstraction Library (GDAL, pronounced "GOODALL"
  # or GOODLE?).  More information on GDAL is available at http://www.gdal.org.
  #
  # MapServer .x can read and display bitmapped (like GIFs), RGB/A (true
  # color), and multispectral (images with more than  bands, like raw LandSat
  # images) rasters.
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_8bit.tif"
    STATUS       OFF #DEFAULT
    TYPE         RASTER
    PROCESSING   "BANDS=1,2,3"
    OFFSITE        
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  LAYER # MODIS WMS map from JPL (or from USGS)
    NAME         modis_jpl
    TYPE         RASTER
    OFFSITE
    STATUS       OFF #OFF
    CONNECTIONTYPE     WMS
    CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
 
    METADATA
      "wms_srs" "EPSG:4326"
      "wms_name" "daily_terra" #"global_mosaic" "daily_aqua"
      "wms_server_version" "1.1.1"
      "wms_format" "image/jpeg"
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS WMS image ends here
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  LAYER # States label layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    LABELITEM    "STATE"
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
      LABEL
        COLOR
        OUTLINECOLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # All map files must come to an end just as all other things must come to...
# End of section , dude!

只有一件事被添加到map文件中：

TEMPLATE 'example1-9.html'

这将告诉MapServer使用页面“example1-9.html”作为模板文件。MapServer将处理此文件并替换它遇到的标记，然后将其发送到Web浏览器。本教程接下来的两个部分就是这样工作的。

这标志着第1节的结束。我希望您在本节中留下足够的知识，了解如何在MapServer映射文件中设置内容。在创建自己的映射文件和应用程序时，我不能过分强调保持MapServer映射文件引用打开的重要性。没有它，我就不会在这个教程中走得太远。

 Section 2: CGI variables and the User Interface

到目前为止，我们只在创建地图时查看了地图文件。在创建Web地图应用程序时，我们通常打算制作用户（应用程序的用户）可以交互更改的映射。也就是说，用户应该能够更改地图的内容（或其中的信息）。为了实现这种交互性，我们使用mapserver HTML模板。

MapServer HTML模板本质上是一个HTML文件，带有一些特定于MapServer的标记——这些标记是MapServer CGI变量带括在方括号“[]”中。当mapserver cgi程序处理一个应用程序时，它首先解析查询字符串和mapfile并生成必要的输出。其中一些输出将需要写入HTML模板文件，您还必须使用web template关键字（或单独的HTML初始化文件）在mapfile中指定该文件。CGI程序将用适当的值替换HTML模板中的所有变量，然后再将其发送回Web浏览器。如果要在Web浏览器上直接查看HTML模板，则不会呈现任何映射，而是会得到空白图像和其他垃圾。

MapServer为Web映射提供了几个变量——您在示例1.9中看到的“img”变量只是一个示例。最初作为绘图接口的一部分设计的核心CGI变量很少，但实际上所有mapfile参数都可以定义为变量。CGI变量的最终参考可在http://www.mapserver.org/cgi/index.html上找到。

我们还可以定义自己的变量——mapserver将把它传递给我们的应用程序。例如，我们可以创建一个名为“root”的变量来表示本教程的根目录——“root”的值将是“/tutorial”。当mapserver cgi程序处理我们的html模板时，它将用“/tutorial”替换他“[根]”标记的每个实例。您将在下面的每个示例中看到这一点。

所以，让我们为我们的应用程序构建一个交互式界面…

Example 2.1 - Pan and Zoom Controls
示例2.1-平移和缩放控件

Web地图应用程序的用户应该能够在地图上平移和缩放…

查看地图文件：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# Map files begin with map keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclose between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  NAME           EX2_
  IMAGETYPE      png24
  EXTENT          -   # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  # When changing any of the mapfile parameters via the web interface, you
  # need to define a TEMPLATEPATTERN.  This is required for security reasons.
  # Since the example filenames in section  begin with "example2" (as in
  # example2-.html or example2-.html), you can use it as the pattern.
  # The template pattern is a regular expression used by MapServer to match the
  # value of map_web_template variable against.
  TEMPLATEPATTERN 'example2*'
 
  # The web object is defined at the level below the map object.  All
  # web-related parameters (I interchange "parameters" and "keyword/value
  # pairs" quite frequently, sorry about that) are defined in this object.
  WEB
    TEMPLATE  'to be replaced by map_web_template variable in section2.html'
    IMAGEPATH '/ms4w/tmp/ms_tmp/'
    IMAGEURL  '/ms_tmp/'
  END # Every object in MapServer must have an END.;)
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
    #  "proj=laea"
    #  "ellps=clrk66"
    #  "lat_0=45"
    #  "lon_0=-100"
    #
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    "init=epsg:2163"
  END # This is the ending of the output projection
 
  #
  # Start of legend
  #
  LEGEND
    KEYSIZE
    LABEL
      TYPE BITMAP
      SIZE MEDIUM
      COLOR
    END
    STATUS ON
  END
 
  # The reference object is used to define a reference map for your mapping
  # application.  This typically involves defining a small image that covers
  # the entire area of the map and defining a box that represents the current
  # view on in relation to the entire area.
  REFERENCE
    IMAGE '../images/ugl_ref1.png' # The reference image
    SIZE   # The size of the reference image in pixels
    EXTENT 201621.496941 -294488.285333 1425518.020722 498254.511514 # The extent of the reference image in map units
    STATUS ON
    MINBOXSIZE  # How small can the reference box be before it gets drawn as a point, in pixels
    MAXBOXSIZE  # The maximum size of the reference box, in pixels
    COLOR - - - # The reference box fill color, negative numbers mean transparent
    OUTLINECOLOR    # The reference box outline color
    MARKERSIZE  # The size of the point marker
    MARKER 'star' # The marker symbol
  END
 
  # A scalebar object is defined one level below the map object.  This object
  # controls how a scalebar is drawn by MapServer.  Scalebars can be embedded
  # in the map itself or can be created as a separate image.  It has an
  # associated MapServer CGI variable called "scalebar" (or [scalebar] when
  # used in the HTML template).
  SCALEBAR
    IMAGECOLOR
    LABEL
      COLOR
      SIZE TINY
    END
    STYLE
    SIZE
    COLOR
    UNITS MILES
    INTERVALS
    TRANSPARENT FALSE
    STATUS ON
  END # Scalebar object ends
 
  # Layer objects, too, are defined beneath the map object.  Be mindful of the
  # order of your layer objects.  MapServer "stacks them" in reverse
  # order--that is, the last layer you define (at the bottom of the map file)
  # will be drawn on top and the first layer you define (right after this
  # comment), will be drawn at the bottom.  Here's my rule: rasters and
  # polygons are defined first, followed by the line layers. The point and
  # annotation layers are defined last.  You can play around with the ordering
  # of your layers until you're satisfied.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       DEFAULT
    TYPE         POLYGON
    REQUIRES     "![modis] OR ![modis_jpl]"
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits, but it's senseless to
    # define more than ten on a "normal" layer.  There are situations,
    # however, where you might have to do it.)
    CLASS
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.
      STYLE
        SYMBOL
        COLOR
      END # And they all must come to an end.
    END # End of this class.
  END # States polygon layer ends here
 
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_idxa.tif"
    STATUS       OFF
    TYPE         RASTER
    OFFSITE         #  
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  LAYER # MODIS WMS map from JPL (or from USGS)
    NAME         modis_jpl
    TYPE         RASTER
    OFFSITE
    STATUS       OFF
    CONNECTIONTYPE     WMS
    CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
 
    METADATA
      "wms_srs" "EPSG:4326"
      "wms_name" "daily_terra" #"global_mosaic" "daily_aqua"
      "wms_server_version" "1.1.1"
      "wms_format" "image/jpeg"
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS WMS image ends here
 
  LAYER # Hydrography layer begins here
    NAME hydro
    TYPE POLYGON
    STATUS OFF
    DATA hydrop_ugl
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM 'FEATURE'
    CLASS
      NAME 'Lakes'
      EXPRESSION /(^B|^C|^L|^R)./
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      NAME 'Rivers'
      EXPRESSION 'Stream'
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      NAME 'Wetlands'
      EXPRESSION 'Swamp or Marsh'
      STYLE
        COLOR
        OUTLINECOLOR
        SYMBOL 'circle'
        SIZE
      END
    END  # CLASS
  END  # LAYER
 
  LAYER # ROADS LAYER
    NAME cty_roads
    GROUP roads
    TYPE LINE
    STATUS OFF
    DATA roads_ugl
    MAXSCALE 
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM 'CLASS1'
    CLASS
      NAME 'Minor Arterial Roads'
      EXPRESSION ''
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      EXPRESSION ''
      STYLE
        COLOR
      END
    END  # CLASS
  END  # ROADS LAYER
 
  LAYER # state highways begin here
    NAME state_hwy
    GROUP roads
    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE LINE
    FILTERITEM 'CLASS1'
    FILTER ''
 
    CLASS
      NAME 'Principal Arterial Roads'
      STYLE
        COLOR
        SIZE
        SYMBOL 'circle'
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highways
 
  LAYER # interstate highways begin here
    NAME interstate
    GROUP roads
#    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE LINE
    FILTERITEM 'CLASS1'
    FILTER ''
 
    CLASS
      NAME "Interstate Hwy."
      STYLE
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highways
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  LAYER
    NAME roads_anno
    GROUP roads
    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE POLYGON
    LABELITEM "SIGN"
    CLASSITEM "CLASS1"
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/sthwy.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/ushwy.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highway annotation
 
  LAYER
    NAME roads_anno1
    GROUP roads
    STATUS OFF
    DATA roads_ugl
    TYPE POLYGON
    LABELITEM "SIGN"
    CLASSITEM "CLASS1"
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/interstate.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END
 
  LAYER # States label layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    LABELITEM    "STATE"
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
      LABEL
        COLOR
        OUTLINECOLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # end of map file

与第1节中的映射一样，我们通过调用mapserv（“/cgi-bin/mapserv.exe”）初始化应用程序。并将我们的mapfile路径和其他参数（“map=/ms4w/apps/tutorial/htdocs/example2-1.map&amp;mode=browse”）传递给它。所以这个页面有一个来自第2节页面的链接，如下所示：

<a href="/cgi-bin/mapserv.exe?
            map=/ms4w/apps/tutorial/htdocs/example2-.map
            &mode=browse&root=/tutorial&program=/cgi-bin/mapserv.exe
            &map_web=template+example2-.html">
      Proceed to Example 2.1</a>

这次我们使用“浏览”模式而不是“地图”。浏览模式告诉mapserv在我们的“/tmp/”目录上创建一个映射（一个图像）。图像路径和名称由名称为“img”的mapserv引用。因此，当mapserv解析我们的HTML模板时，它将用正确的图像路径替换“[img]”/ms_tmp/ex2_156231592315176.png。

你可以用这张地图做一些事情。首先，您可以单击图像的任何部分，地图将刷新并使您单击的点居中。这是平移。如果单击“地图控件”下拉框，可以选择“放大”或“缩小”值。如果将其设置为“放大2倍”，然后单击地图的任何部分，地图将刷新、放大，并以单击的点为中心。反之，如果你缩小。当选择“放大”或“缩小”值并单击“刷新”按钮时，地图将刷新并放大或缩小上一个地图的中心。您可以随时使用“刷新”按钮刷新地图。

缩放/平移控件使用内部mapserver cgi变量。此示例演示如何使用“zoom”变量。缩放值决定放大或缩小的距离。如果值为“0”，则MapServer将根据用户的鼠标单击重新输入图像。如果该值大于“0”，则CGI程序放大（地图的当前比例乘以缩放值）。如果是负数，那么CGI程序会缩小（将当前比例除以缩放值）。其他可用于控制缩放和平移的变量有“zoomdir”和“zoomsize”。这两个变量的作用与“缩放”差不多——“zoomdir”控制缩放方向，“zoomsize”控制放大或缩小的距离。请查看osgeo库或mapserver wiki上的其他示例，以获取其他缩放/平移控制选项。

尝试将“地图模式”从“浏览”更改为“地图”。单击刷新时会发生什么？记住，当我们使用“模式=映射”时，mapserver会返回一个静态映射…它忽略HTML模板，只将映射图像直接流式传输到浏览器。

尽管添加了更多的数据层，但它仍然与第一节中的映射文件相似。我没有什么新的东西可以解释这个地图文件，但是如果你对一些新的关键字感兴趣，请查阅地图文件参考页。

现在，看看HTML模板文件。您会注意到这实际上是一个调用mapserver cgi程序的HTML表单。因为它是一个表单，所以您可以使用单选按钮和复选框以及下拉框来实现您的界面。不要觉得受这个例子的限制——有创造力是件好事。；）有关详细信息，请查看HTML模板引用页。

……他们还应该能够打开和关闭地图上的图层。
示例2.2-层控制

能够打开和关闭地图层是Web映射应用程序的标准功能。使用表单对象作为控件有很多方法可以实现这一点。您可以使用下拉框/菜单、复选框和/或单选按钮。在本例中，您将看到如何使用复选框和放置框实现层选择。

这里是mapfile：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# Map files begin with map keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclose between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  NAME           EX2_
  IMAGETYPE      png24
  EXTENT          -   # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  # When changing any of the mapfile parameters via the web interface, you
  # need to define a TEMPLATEPATTERN.  This is required for security reasons.
  # Since the example filenames in section  begin with "example2" (as in
  # example2-.html or example2-.html), you can use it as the pattern.
  # The template pattern is a regular expression used by MapServer to match the
  # value of map_web_template variable against.
  TEMPLATEPATTERN 'example2*'
 
  # The web object is defined at the level below the map object.  All
  # web-related parameters (I interchange "parameters" and "keyword/value
  # pairs" quite frequently, sorry about that) are defined in this object.
  WEB
    TEMPLATE  'to be replaced by map_web_template variable in section2.html'
    IMAGEPATH '/ms4w/tmp/ms_tmp/'
    IMAGEURL  '/ms_tmp/'
  END # Every object in MapServer must have an END.;)
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
    #  "proj=laea"
    #  "ellps=clrk66"
    #  "lat_0=45"
    #  "lon_0=-100"
    #
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    "init=epsg:2163"
  END # This is the ending of the output projection
 
  #
  # Start of legend
  #
  LEGEND
    KEYSIZE
    LABEL
      TYPE BITMAP
      SIZE MEDIUM
      COLOR
    END
    STATUS ON
  END
 
  # The reference object is used to define a reference map for your mapping
  # application.  This typically involves defining a small image that covers
  # the entire area of the map and defining a box that represents the current
  # view on in relation to the entire area.
  REFERENCE
    IMAGE '../images/ugl_ref1.png' # The reference image
    SIZE   # The size of the reference image in pixels
    EXTENT 201621.496941 -294488.285333 1425518.020722 498254.511514 # The extent of the reference image in map units
    STATUS ON
    MINBOXSIZE  # How small can the reference box be before it gets drawn as a point, in pixels
    MAXBOXSIZE  # The maximum size of the reference box, in pixels
    COLOR - - - # The reference box fill color, negative numbers mean transparent
    OUTLINECOLOR    # The reference box outline color
    MARKERSIZE  # The size of the point marker
    MARKER 'star' # The marker symbol
  END
 
  # A scalebar object is defined one level below the map object.  This object
  # controls how a scalebar is drawn by MapServer.  Scalebars can be embedded
  # in the map itself or can be created as a separate image.  It has an
  # associated MapServer CGI variable called "scalebar" (or [scalebar] when
  # used in the HTML template).
  SCALEBAR
    IMAGECOLOR
    LABEL
      COLOR
      SIZE TINY
    END
    STYLE
    SIZE
    COLOR
    UNITS MILES
    INTERVALS
    TRANSPARENT FALSE
    STATUS ON
  END # Scalebar object ends
 
  # Layer objects, too, are defined beneath the map object.  Be mindful of the
  # order of your layer objects.  MapServer "stacks them" in reverse
  # order--that is, the last layer you define (at the bottom of the map file)
  # will be drawn on top and the first layer you define (right after this
  # comment), will be drawn at the bottom.  Here's my rule: rasters and
  # polygons are defined first, followed by the line layers. The point and
  # annotation layers are defined last.  You can play around with the ordering
  # of your layers until you're satisfied.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       DEFAULT
    TYPE         POLYGON
    REQUIRES     "![modis] OR ![modis_jpl]"
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits, but it's senseless to
    # define more than ten on a "normal" layer.  There are situations,
    # however, where you might have to do it.)
    CLASS
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.
      STYLE
        SYMBOL
        COLOR
      END # And they all must come to an end.
    END # End of this class.
  END # States polygon layer ends here
 
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_idxa.tif"
    STATUS       OFF
    TYPE         RASTER
    OFFSITE         #  
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  LAYER # MODIS WMS map from JPL (or from USGS)
    NAME         modis_jpl
    TYPE         RASTER
    OFFSITE
    STATUS       OFF
    CONNECTIONTYPE     WMS
    CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
 
    METADATA
      "wms_srs" "EPSG:4326"
      "wms_name" "daily_terra" #"global_mosaic" "daily_aqua"
      "wms_server_version" "1.1.1"
      "wms_format" "image/jpeg"
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS WMS image ends here
 
  LAYER # Hydrography layer begins here
    NAME hydro
    TYPE POLYGON
    STATUS OFF
    DATA hydrop_ugl
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM 'FEATURE'
    CLASS
      NAME 'Lakes'
      EXPRESSION /(^B|^C|^L|^R)./
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      NAME 'Rivers'
      EXPRESSION 'Stream'
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      NAME 'Wetlands'
      EXPRESSION 'Swamp or Marsh'
      STYLE
        COLOR
        OUTLINECOLOR
        SYMBOL 'circle'
        SIZE
      END
    END  # CLASS
  END  # LAYER
 
  LAYER # ROADS LAYER
    NAME cty_roads
    GROUP roads
    TYPE LINE
    STATUS OFF
    DATA roads_ugl
    MAXSCALE 
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM 'CLASS1'
    CLASS
      NAME 'Minor Arterial Roads'
      EXPRESSION ''
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      EXPRESSION ''
      STYLE
        COLOR
      END
    END  # CLASS
  END  # ROADS LAYER
 
  LAYER # state highways begin here
    NAME state_hwy
    GROUP roads
    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE LINE
    FILTERITEM 'CLASS1'
    FILTER ''
 
    CLASS
      NAME 'Principal Arterial Roads'
      STYLE
        COLOR
        SIZE
        SYMBOL 'circle'
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highways
 
  LAYER # interstate highways begin here
    NAME interstate
    GROUP roads
#    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE LINE
    FILTERITEM 'CLASS1'
    FILTER ''
 
    CLASS
      NAME "Interstate Hwy."
      STYLE
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highways
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  LAYER
    NAME roads_anno
    GROUP roads
    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE POLYGON
    LABELITEM "SIGN"
    CLASSITEM "CLASS1"
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/sthwy.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/ushwy.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highway annotation
 
  LAYER
    NAME roads_anno1
    GROUP roads
    STATUS OFF
    DATA roads_ugl
    TYPE POLYGON
    LABELITEM "SIGN"
    CLASSITEM "CLASS1"
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/interstate.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END
 
  LAYER # States label layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    LABELITEM    "STATE"
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
      LABEL
        COLOR
        OUTLINECOLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # end of map file

注意图层的STATUS已经被改为OFF，除了“States”多边形背景。

状态背景保留为默认设置，因此在绘制地图时，如果不打开任何图层，则始终会显示某些内容。应用程序的用户应该能够控制打开或关闭哪些层。
如果您查看HTML模板的源代码，您将了解mapserv如何打开/关闭层。

地图应始终包含一个scaleBar。
示例2.3-添加scaleBar

这里是mapfile文件：

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
#
#
# Map files begin with map keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclose between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  NAME           EX2_
  IMAGETYPE      png24
  EXTENT          -   # LAEA
  #EXTENT         -97.5 41.619778 -82.122902 49.38562 # Geographic
  SIZE
  SHAPEPATH      "../data"
  SYMBOLSET      "../symbols/symbols35.sym"
  FONTSET        "../fonts/fonts.list"
 
  # When changing any of the mapfile parameters via the web interface, you
  # need to define a TEMPLATEPATTERN.  This is required for security reasons.
  # Since the example filenames in section  begin with "example2" (as in
  # example2-.html or example2-.html), you can use it as the pattern.
  # The template pattern is a regular expression used by MapServer to match the
  # value of map_web_template variable against.
  TEMPLATEPATTERN 'example2*'
 
  # The web object is defined at the level below the map object.  All
  # web-related parameters (I interchange "parameters" and "keyword/value
  # pairs" quite frequently, sorry about that) are defined in this object.
  WEB
    TEMPLATE  'to be replaced by map_web_template variable in section2.html'
    IMAGEPATH '/ms4w/tmp/ms_tmp/'
    IMAGEURL  '/ms_tmp/'
  END # Every object in MapServer must have an END.;)
 
  # The projection object is typically used within the map and the layer
  # objects. You only define it once within the map object and this definition
  # becomes your output projection--MapServer will render your maps in this
  # projection.  You also use the projection object within the layer object to
  # define your input projection.  Your layers can be in different
  # projections--MapServer will reproject them into your output projection.
  # If no projection is defined within the layer object, MapServer assumes
  # your input projection is the same as your output projection.  This is not
  # a required object unless you're creating a map file that supports one of
  # the OGC interoperability web services specifications (WMS/WFS/WCS).
  PROJECTION
    # Projection parameters can be defined in two ways...
    # This is the traditional Proj. definition of Lambert Azimuthal Equal-Area
    # projection for the Continental U.S.
    #  "proj=laea"
    #  "ellps=clrk66"
    #  "lat_0=45"
    #  "lon_0=-100"
    #
    # Alternatively, you can specify an EPSG code.
    # This is the EPSG code for Lambert Azimuthal Equal-Area
    # projection for the U.S.
    "init=epsg:2163"
  END # This is the ending of the output projection
 
  #
  # Start of legend
  #
  LEGEND
    KEYSIZE
    LABEL
      TYPE BITMAP
      SIZE MEDIUM
      COLOR
    END
    STATUS ON
  END
 
  # The reference object is used to define a reference map for your mapping
  # application.  This typically involves defining a small image that covers
  # the entire area of the map and defining a box that represents the current
  # view on in relation to the entire area.
  REFERENCE
    IMAGE '../images/ugl_ref1.png' # The reference image
    SIZE   # The size of the reference image in pixels
    EXTENT 201621.496941 -294488.285333 1425518.020722 498254.511514 # The extent of the reference image in map units
    STATUS ON
    MINBOXSIZE  # How small can the reference box be before it gets drawn as a point, in pixels
    MAXBOXSIZE  # The maximum size of the reference box, in pixels
    COLOR - - - # The reference box fill color, negative numbers mean transparent
    OUTLINECOLOR    # The reference box outline color
    MARKERSIZE  # The size of the point marker
    MARKER 'star' # The marker symbol
  END
 
  # A scalebar object is defined one level below the map object.  This object
  # controls how a scalebar is drawn by MapServer.  Scalebars can be embedded
  # in the map itself or can be created as a separate image.  It has an
  # associated MapServer CGI variable called "scalebar" (or [scalebar] when
  # used in the HTML template).
  SCALEBAR
    IMAGECOLOR
    LABEL
      COLOR
      SIZE TINY
    END
    STYLE
    SIZE
    COLOR
    UNITS MILES
    INTERVALS
    TRANSPARENT FALSE
    STATUS ON
  END # Scalebar object ends
 
  # Layer objects, too, are defined beneath the map object.  Be mindful of the
  # order of your layer objects.  MapServer "stacks them" in reverse
  # order--that is, the last layer you define (at the bottom of the map file)
  # will be drawn on top and the first layer you define (right after this
  # comment), will be drawn at the bottom.  Here's my rule: rasters and
  # polygons are defined first, followed by the line layers. The point and
  # annotation layers are defined last.  You can play around with the ordering
  # of your layers until you're satisfied.
 
  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       DEFAULT
    TYPE         POLYGON
    REQUIRES     "![modis] OR ![modis_jpl]"
 
    # Here's an example of the input projection definition.
    # EPSG: is code for geographic (latlong) projection
    # using the WGS84 datum
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
 
    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits, but it's senseless to
    # define more than ten on a "normal" layer.  There are situations,
    # however, where you might have to do it.)
    CLASS
      EXPRESSION 'land'
 
      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.
      STYLE
        SYMBOL
        COLOR
      END # And they all must come to an end.
    END # End of this class.
  END # States polygon layer ends here
 
  LAYER # MODIS raster layer begins here
    NAME         modis
    DATA         "raster/mod09a12003161_ugl_ll_idxa.tif"
    STATUS       OFF
    TYPE         RASTER
    OFFSITE         #  
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS raster layer ends here
 
  LAYER # MODIS WMS map from JPL (or from USGS)
    NAME         modis_jpl
    TYPE         RASTER
    OFFSITE
    STATUS       OFF
    CONNECTIONTYPE     WMS
    CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
 
    METADATA
      "wms_srs" "EPSG:4326"
      "wms_name" "daily_terra" #"global_mosaic" "daily_aqua"
      "wms_server_version" "1.1.1"
      "wms_format" "image/jpeg"
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # MODIS WMS image ends here
 
  LAYER # Hydrography layer begins here
    NAME hydro
    TYPE POLYGON
    STATUS OFF
    DATA hydrop_ugl
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM 'FEATURE'
    CLASS
      NAME 'Lakes'
      EXPRESSION /(^B|^C|^L|^R)./
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      NAME 'Rivers'
      EXPRESSION 'Stream'
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      NAME 'Wetlands'
      EXPRESSION 'Swamp or Marsh'
      STYLE
        COLOR
        OUTLINECOLOR
        SYMBOL 'circle'
        SIZE
      END
    END  # CLASS
  END  # LAYER
 
  LAYER # ROADS LAYER
    NAME cty_roads
    GROUP roads
    TYPE LINE
    STATUS OFF
    DATA roads_ugl
    MAXSCALE 
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM 'CLASS1'
    CLASS
      NAME 'Minor Arterial Roads'
      EXPRESSION ''
      STYLE
        COLOR
      END
    END  # CLASS
    CLASS
      EXPRESSION ''
      STYLE
        COLOR
      END
    END  # CLASS
  END  # ROADS LAYER
 
  LAYER # state highways begin here
    NAME state_hwy
    GROUP roads
    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE LINE
    FILTERITEM 'CLASS1'
    FILTER ''
 
    CLASS
      NAME 'Principal Arterial Roads'
      STYLE
        COLOR
        SIZE
        SYMBOL 'circle'
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highways
 
  LAYER # interstate highways begin here
    NAME interstate
    GROUP roads
#    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE LINE
    FILTERITEM 'CLASS1'
    FILTER ''
 
    CLASS
      NAME "Interstate Hwy."
      STYLE
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highways
 
  LAYER # States line layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    CLASS
      NAME       'State Boundary'
      EXPRESSION 'land'
      STYLE
        SYMBOL     'line5'
        COLOR
        SIZE
      END
    END
  END # States line layer ends here
 
  LAYER
    NAME roads_anno
    GROUP roads
    MAXSCALE
    STATUS OFF
    DATA roads_ugl
    TYPE POLYGON
    LABELITEM "SIGN"
    CLASSITEM "CLASS1"
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/sthwy.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/ushwy.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END # highway annotation
 
  LAYER
    NAME roads_anno1
    GROUP roads
    STATUS OFF
    DATA roads_ugl
    TYPE POLYGON
    LABELITEM "SIGN"
    CLASSITEM "CLASS1"
    CLASS
      EXPRESSION ""
      STYLE
        COLOR    # dummy color
        SYMBOL '../symbols/interstate.png'
      END
      LABEL
        MINFEATURESIZE
        MINDISTANCE
        POSITION CC
        SIZE TINY
        COLOR
      END
    END
 
    PROJECTION
      "init=epsg:4326"
    END
  END
 
  LAYER # States label layer begins here
    NAME         states
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON
 
    PROJECTION
      "init=epsg:4326"
    END
 
    CLASSITEM    "CLASS"
    LABELITEM    "STATE"
    CLASS
      EXPRESSION 'land'
      STYLE
        COLOR      - - -
      END
      LABEL
        COLOR
        OUTLINECOLOR
        SHADOWCOLOR
        SHADOWSIZE
        TYPE TRUETYPE
        FONT arial-bold
        SIZE
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE
        BUFFER
      END # end of label
    END # end of class
  END # States label layer ends here
  # End of LAYER DEFINITIONS -------------------------------
 
END # end of map file

如果用户要浏览地图，则应提供参考地图。
示例2.4-添加参考图

HTML Template：

<!-- MapServer Template -->
<html>
<head>
<title>MapServer .x Tutorial</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link type="text/css" rel="stylesheet" href="/tutorial/ms35.css" />
</head>
 
<body bgcolor="#FFFFFF" text="#000000">
<table align="center" border=""><tr>
    <td> <h3 align="center">Example 2.4: Adding a Reference Map</h3>
 
<!-- START OF MAPSERVER FORM -->
<form name="mapserv" method="GET" action="/cgi-bin/mapserv.exe">
 
<!-- HIDDEN MAPSERVER CGI VARIABLES -->
    <input type="hidden" name="map" value="[map]">
    <input type="hidden" name="imgext" value="[mapext]">
    <input type="hidden" name="imgxy" value="199.5 149.5">
<table width="" border="" align="center">
  <tr>
    <td>
    <table width="" border="" align="center">
      <tr>
        <td colspan="">Select Layers:
<!-- SPECIFY VECTOR LAYERS -->
          <input type="checkbox" name="layer" value="states"
          [states_check] checked>State Boundaries&nbsp;
              <input type="checkbox" name="layer" value="hydro"
              [hydro_check]>Water Features&nbsp;
          <input type="checkbox" name="layer" value="roads"
          [roads_check]>Roads<br>
 
<!-- SPECIFY RASTER LAYERS -->
          Select Background:
          <select name="layer">
        <option value=" " [ _select]>No Background</option>
        <option value="modis_jpl" [modis_jpl_select]>
        Daily MODIS Image</option>
        <option value="modis" [modis_select]>
        MODIS Surface Reflectance</option>
          </select>
        </td>
      </tr>
      <tr>
        <td>
 
<!-- SPECIFY MAP MODE -->
          <div align="center">Map Mode:<br>
        <select name="mode">
          <option value="browse" [browse_select]>Browse</option>
        </select>
          </div>
        </td>
        <td>
<!-- FORM SUBMIT BUTTON -->
          <div align="center">
        <input type="submit" name="submit" value="Refresh">
          </div>
        </td>
        <td>
<!-- ZOOM/PAN CONTROLS -->
          <div align="center">Map Control: <br>
        <select name="zoom">
          <option value="" [zoom_4_select]>Zoom In 4x</option>
          <option value="" [zoom_3_select]>Zoom In 3x</option>
          <option value="" [zoom_2_select]>Zoom In 2x</option>
          <option value="" [zoom_1_select]>Recenter</option>
          <option value="-2" [zoom_-2_select]>Zoom Out 2x</option>
          <option value="-3" [zoom_-3_select]>Zoom Out 3x</option>
          <option value="-4" [zoom_-4_select]>Zoom Out 4x</option>
        </select>
          </div>
        </td>
<!-- REFERENCE COLUMN -->
        <td rowspan="" valign="top">
          <p>Reference:<br>
              <input type="image" name="ref" src="[ref]" border=""></p>
        </td>
      </tr>
      <tr>
<!-- DISPLAY THE MAPSERVER-CREATED MAP IMAGE -->
        <td colspan="" align="center" valign="top">
          <input type="image" name="img" src="[img]" width=""
           height="" border="">
        </td>
      </tr>
    </table>
    </td>
  </tr>
</table>
</form>
</body>
</html>

这段代码中有趣的部分是标签，即[缩放\选择]。当mapserv看到这样的标记时，它将评估是否选择了值（“1”）。如果选中，则MapServ会将此选项标记为“已选中”。再次，转到示例2.1并“查看”代码。“recenter”选项应该是“selected”（这样当我们再次提交表单时，“zoom”的值将是“1”）。

最后一个标签是“[img]”标签。正如您将注意到的，它是表单输入对象的一部分。“[img]”将替换为mapserv生成的映像的完整路径和名称。

一旦mapserver替换了所有标记，它将向浏览器发送一个合适的HTML表单。用户将再次能够进行更改。

像任何好的地图一样，它应该包括一个传说。
示例2.5-添加图例

这里是HTML模板源代码：

<!-- MapServer Template -->
<html>
<head>
<title>MapServer .x Tutorial</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link type="text/css" rel="stylesheet" href="/tutorial/ms35.css" />
</head>
 
<body bgcolor="#FFFFFF" text="#000000">
<table align="center" border=""><tr>
    <td> <h3 align="center">Example 2.5: Adding a Legend</h3>
 
<!-- START OF MAPSERVER FORM -->
<form name="mapserv" method="GET" action="/cgi-bin/mapserv.exe">
 
<!-- HIDDEN MAPSERVER CGI VARIABLES -->
    <input type="hidden" name="map" value="[map]">
    <input type="hidden" name="imgext" value="[mapext]">
    <input type="hidden" name="imgxy" value="199.5 149.5">
<table width="" border="" align="center">
  <tr>
    <td>
    <table width="" border="" align="center">
      <tr>
        <td colspan="">Select Layers:
<!-- SPECIFY VECTOR LAYERS -->
          <input type="checkbox" name="layer" value="states"
          [states_check] checked>
              State Boundaries&nbsp;
              <input type="checkbox" name="layer" value="hydro"
              [hydro_check]>
          Water Features&nbsp;
          <input type="checkbox" name="layer" value="roads"
          [roads_check]>
          Roads<br>
 
<!-- SPECIFY RASTER LAYERS -->
          Select Background:
          <select name="layer">
        <option value=" " [ _select]>No Background</option>
        <option value="modis_jpl" [modis_jpl_select]>
        Daily MODIS Image</option>
        <option value="modis" [modis_select]>
        MODIS Surface Reflectance</option>
          </select>
        </td>
      </tr>
      <tr>
        <td>
 
<!-- SPECIFY MAP MODE -->
          <div align="center">Map Mode:<br>
        <select name="mode">
          <option value="browse" [browse_select]>Browse</option>
        </select>
          </div>
        </td>
        <td>
<!-- FORM SUBMIT BUTTON -->
          <div align="center">
        <input type="submit" name="submit" value="Refresh">
          </div>
        </td>
        <td>
<!-- ZOOM/PAN CONTROLS -->
          <div align="center">Map Control: <br>
        <select name="zoom">
          <option value="" [zoom_4_select]>Zoom In 4x</option>
          <option value="" [zoom_3_select]>Zoom In 3x</option>
          <option value="" [zoom_2_select]>Zoom In 2x</option>
          <option value="" [zoom_1_select]>Recenter</option>
          <option value="-2" [zoom_-2_select]>Zoom Out 2x</option>
          <option value="-3" [zoom_-3_select]>Zoom Out 3x</option>
          <option value="-4" [zoom_-4_select]>Zoom Out 4x</option>
        </select>
          </div>
        </td>
<!-- REFERENCE AND LEGEND COLUMN -->
        <td rowspan="" valign="top">
          <p>Reference:<br>
        <img name="ref" src="[ref]"></p>
          <p>Legend:<br>
        <img name="legend" src="[legend]"></p>
      </td>
      </tr>
      <tr>
<!-- DISPLAY THE MAPSERVER-CREATED MAP IMAGE -->
        <td colspan="" align="center" valign="top">
          <input type="image" name="img" src="[img]" width=""
           height="" border="">
        </td>
      </tr>
    </table>
    </td>
  </tr>
</table>
</form>
</body>
</html>

这段代码中有趣的部分是标签，即[缩放\选择]。当mapserv看到这样的标记时，它将评估是否选择了值（“1”）。如果选中，则MapServ会将此选项标记为“已选中”。再次，转到示例2.1并“查看”代码。“recenter”选项应该是“selected”（这样当我们再次提交表单时，“zoom”的值将是“1”）。
最后一个标签是“[img]”标签。正如您将注意到的，它是表单输入对象的一部分。“[img]”将替换为mapserv生成的映像的完整路径和名称。
一旦mapserver替换了所有标记，它将向浏览器发送一个合适的HTML表单。用户将再次能够进行更改。