[Android5 系列—] 1. 构建一个简单的用户界面

前言

安卓应用的用户界面是构建在View 和ViewGroup 这两个物件的层级之上的。 View 就是一般的UI组件。像button，输入框等。

viewGroup 是一些不可见的view的容器，用来定义子View 怎样布局。 相似在一个网格或是一个垂直列表。

安卓提供了一套XML的标签词汇用来定义UI的页面显示。

定义一个线性布局

1. 在 res/layout 文件夹下。打开 activity_my.xml (my 是您定义的activity 的名字)

在创建project师包括的 BlankActivity 模板文件，包括一个 RelativeLayout 的根视图和一个  TextView 的子视图。

2. 删除  <TextView> 元素

3. 将 <RelativeLayout> 改动成 <LinearLayout>.

4. 加入 android:orientation  属性 ，并把值设置成  "horizontal".

5. 移除 android:padding 和 tools:context 的属性

改动后的文件相似：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >
</LinearLayout>

LinearLayout  是一个视图组(ViewGroup的一个子类)，这个布局配合设置android:orientation把子视图布置成水平或竖直方向。

android:layout_width 和 android:layout_height  这两个属性用来设置布局的大小。这个值设置成 "match_parent" 就会撑开他的长宽和父View 适应。

过多关于布局的内容，能够參考官方介绍：

http://developer.android.com/guide/topics/ui/declaring-layout.html

加入一个文本输入框

1. 在 activity_my.xml ，在<LinearLayout> 中，定义<EditText>元素，属性 “id”的值设置成 @+id/edit_message.

2. layout_width 和 layout_height的属性值设置成"wrap_content"

3. 定义 hint 的属性，值为 edit_message.

res/layout/activity_my.xml  ， 完整的定义相似：

<EditText android:id="@+id/edit_message"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:hint="@string/edit_message" />

属性及属性值说明

android:id  -- 

@+id/edit_message

@ 的意思是： 但须要从XML 读取资源物件时

+: 但首次定义一个资源ID时，须要加上 "+“号。 在编译APP的时候, SDK 工具会通过ID 名字在gen\R.java中创建一个新的资源ID/

id: 是类型(处理id类型， 还有string 等类型)

edit_message: 这个以下就会介绍怎样创建

android:layout_width 和 android:layout_height

"wrap_content"

替代设置实际的宽度和高度。 wrap_content 这个值能够让view 填充整个内容。

android:hint

当 输入框为空时。 设置的默认显示字符串。

加入字符串资源

默认状况。 安卓project会导入字符串资源文件 res/values/strings.xml. 

这里就加入以下上面用到的  "edit_message" 等

1.  打开 res/values/strings.xml

2.  加入一行 "edit_message"， 值设置成  "Enter a message".

3. 再加入一行， "button_send" 值设置成 "Send".

res/values/strings.xml， 结果相似

<?

xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">My First App</string>
    <string name="edit_message">Enter a message</string>
    <string name="button_send">Send</string>
    <string name="action_settings">Settings</string>
    <string name="title_activity_main">MainActivity</string>
</resources>

加入一个button

1. 打开 activity_my.xml

2. 在 <LinearLayout> 中，在<EditText> 后加入一个<Button> 元素

3. 设置button的宽度和高度的属性值为 "wrap_content"

4. 定义   android:text 用来定义button的显示。

res/layout/activity_my.xml   

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >
      <EditText android:id="@+id/edit_message"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:hint="@string/edit_message" />
      <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_send" />
</LinearLayout>

使输入框填充整个屏幕

以上的部分， 执行后效果例如以下：

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" alt="" />

能够看到， 输入框并没有占满这个屏幕。

设置 <EditText> 的属性  layout_weight  和  layout_width

<EditText
    android:layout_weight="1"
    android:layout_width="0dp"
    ... />

再执行看一下 ....