arcengine C#关于动态添加图层

动态加载影像图层为例

研究了两三天算是弄出来了。本例适合影像数据量特别的大程序使用，可以动态的添加删除影像数据，还有不完善的地方，不过基本满足要求。

1.首先得到关键点的图层

m_Map = axMapControl.Map;

int l = 0;

int f = 0;

for (int j = 0; j < m_Map.LayerCount; j++)

{

if (m_Map.get_Layer(j).Name == "Points")

{

l = j;//获得Points图层

}

}

2.取得该范围

double xmax = env.XMax;

double ymax = env.YMax;

double xmin = env.XMin;

double ymin = env.YMin;

3.经纬度以及名称字段的属性信息存入arraylist

ArrayList aList = new ArrayList();

ArrayList bList = new ArrayList();

ArrayList nList = new ArrayList();

IFeatureLayer ilayer = (IFeatureLayer)m_Map.get_Layer(l);//得到点图层

IFeatureCursor pFeatureCursor;

pFeatureCursor = ilayer.FeatureClass.Search(null, false);

IFeature pFeature;

pFeature = pFeatureCursor.NextFeature();

while (pFeature != null)

{

string jdValue = Convert.ToString(pFeature.get_Value(4));

string wdValue = Convert.ToString(pFeature.get_Value(5));

string name = Convert.ToString(pFeature.get_Value(2));

pFeature = pFeatureCursor.NextFeature();

aList.Add(jdValue);//经纬度以及name存入arraylist

bList.Add(wdValue);

nList.Add(name);

}

4.遍历arraylist并判断点是否在可视范围内

if (m_Map.MapScale < 400000)

{

for (int j = 0; j < 35; j++)

{

double jd = double.Parse(aList[j].ToString());

double wd = double.Parse(bList[j].ToString());

//判断土层中是否已经存在某个影像数据，若存在则不进行坐标的判断

if (jd >= xmin && jd <= xmax)

{

if (wd >= ymin && wd <= ymax)

{  nameid = nList[j].ToString();//获得name属性

for (int q = 0; q < axMapControl.Map.LayerCount; q++)

{

temp = getname == nameid + ".tif";

getname = Convert.ToString(axMapControl.get_Layer(q).Name);

if(temp)

indexa = q - 1;

}

5.调用添加影像数据函数dynamicadd()（目前是本地）

//动态加载删格数据

public void dynamicadd(string strFullPath)

{

int Index = strFullPath.LastIndexOf("\\");

string fileName = strFullPath.Substring(Index + 1);

string filePath = strFullPath.Substring(0, Index);

IWorkspaceFactory workspaceFactory = new RasterWorkspaceFactory();

IRasterWorkspace rasterWorkspace = (IRasterWorkspace)workspaceFactory.OpenFromFile(filePath, 0);

IRasterDataset rasterDataset = (IRasterDataset)rasterWorkspace.OpenRasterDataset(fileName);

IRasterLayer rasterLayer = new RasterLayerClass();

rasterLayer.CreateFromDataset(rasterDataset);

axMapControl.AddLayer(rasterLayer, 2);//有心的话你会发现此函数与axMapControl.Map.AddLayer()的区别（没有插入的图层序号），可以试试哦！

}

6.判断是否已经动态加载

if (temp)

{

//MessageBox.Show(Convert.ToString(axMapControl.get_Layer(indexa).Name));//测试

axMapControl.get_Layer(indexa).MinimumScale = 250000;//设定这个图层的可见范围？

return;

}

else

{

string strFullPath = "";

strFullPath = Application.StartupPath + @"\\data\影像\" + nameid + ".tif";//这里就是影像图层的路径

dynamicadd(strFullPath);

axMapControl.get_Layer(2).MinimumScale = 250000;

break;

}

7将影像图层控制在五个以内超过了就删除

clearLayer.Add(nameid);

axMapControl.get_Layer(2).MinimumScale = 250000;

if (clearLayer.Count > 5)//当图层超过5个时清除最早加载的图层（应该是不在视图范围内的）

{

for (int e = 0; e < axMapControl.LayerCount;e++ )

{

if(axMapControl.get_Layer(e).Name.ToString() == clearLayer[0].ToString()+".tif")

{

//ILayer layer = null;

//layer = axMapControl.Map.get_Layer(e);

axMapControl.DeleteLayer(e);

}

}

8.综上所述

调用部分

//范围
IEnvelope env = axMapControl.Extent;//获取范围
fanwei(env);//可以返回string nameid再根据nameid寻找路径

主要声明的字段以及arraylist

string nameid = "";//关键的传值字段，连接影像数据的路径

string getname = "";//

bool temp =false;//判断是否已经加载的bool类型变量

ArrayList clearLayer = new ArrayList();

主要函数部分

public void fanwei(IEnvelope env)

{

m_Map = axMapControl.Map;

int l = 0;

int f = 0;

for (int j = 0; j < m_Map.LayerCount; j++)

{

if (m_Map.get_Layer(j).Name == "Points")

{

l = j;//获得Points图层为以后得到图层传递l

}

}

double xmax = env.XMax;

double ymax = env.YMax;

double xmin = env.XMin;

double ymin = env.YMin;//屏幕范围参数取值

ArrayList aList = new ArrayList();

ArrayList bList = new ArrayList();

ArrayList nList = new ArrayList();//用来存储经纬度以及名称字段的arraylist

IFeatureLayer ilayer = (IFeatureLayer)m_Map.get_Layer(l);//得到点图层

IFeatureCursor pFeatureCursor;

pFeatureCursor = ilayer.FeatureClass.Search(null, false);

IFeature pFeature;

pFeature = pFeatureCursor.NextFeature();//用来获取字段值的关键

while (pFeature != null)

{

string jdValue = Convert.ToString(pFeature.get_Value(4));

string wdValue = Convert.ToString(pFeature.get_Value(5));

string name = Convert.ToString(pFeature.get_Value(2));

pFeature = pFeatureCursor.NextFeature();

aList.Add(jdValue);//经纬度以及name存入arraylist

bList.Add(wdValue);

nList.Add(name);

}

if (m_Map.MapScale < 400000)//比例尺大于此值将进行判断

{

for (int j = 0; j < 35; j++)//在这里我知道共有35个点

{

double jd = double.Parse(aList[j].ToString());

double wd = double.Parse(bList[j].ToString());

//判断点是否在可视范围内，在范围内则取值nameid与影像数据路径相关联

//判断图层中是否已经存在某个影像数据，若存在则不进行坐标的判断

if (jd >= xmin && jd <= xmax)

{

if (wd >= ymin && wd <= ymax)

{

nameid = nList[j].ToString();//获得name属性

for (int q = 0; q < axMapControl.Map.LayerCount; q++)

{

temp = (getname == nameid + ".tif");

getname = Convert.ToString(axMapControl.get_Layer(q).Name);

if(temp)

{

indexa = q - 1;

break;//很重要！！！！

}

}

if (temp)

{

for (int e = 0; e < axMapControl.LayerCount; e++)
{
for (int r = 0; r < clearLayer.Count; r++)
{
if (axMapControl.get_Layer(e).Name.ToString() == clearLayer[r].ToString() + ".tif")
{
//ILayer layer = null;
//layer = axMapControl.Map.get_Layer(e);
axMapControl.get_Layer(e).MinimumScale = 250000;
}
}
}

return;//return还是break要注意

}

else

{

string strFullPath = "";

strFullPath = Application.StartupPath + @"\\data\影像\" + nameid + ".tif";

dynamicadd(strFullPath);

clearLayer.Add(nameid);

　　　　　　　　　　

if (clearLayer.Count > 5)//当图层超过5个时清除最早加载的图层（应该是不在视图范围内的）

{

for (int e = 0; e < axMapControl.LayerCount;e++ )

{

if(axMapControl.get_Layer(e).Name.ToString() == clearLayer[0].ToString()+".tif")

{

//ILayer layer = null;

//layer = axMapControl.Map.get_Layer(e);

axMapControl.DeleteLayer(e);

}

}

}

break;

}                        }

}

}

}

}

如果有问题欢迎提出建议！刚刚做出来可能有需要完善的地方