Layout Resource官方教程(3)在layout中用include嵌入其它layout

简介

<include>Includes a layout file into this layout.

类似 #include ，把layout展开在include处

attributes:

layout	Layout resource. Required. Reference to a layout resource.
android:id	Resource ID. Overrides the ID given to the root view in the included layout.
android:layout_height	Dimension or keyword. Overrides the height given to the root view in the included layout. Only effective if android:layout_width is also declared.
android:layout_width	Dimension or keyword. Overrides the width given to the root view in the included layout. Only effective if android:layout_height is also declared.

　　You can include any other layout attributes in the <include> that are supported by the root element in the included layout and they will override those defined in the root element.

注意，findViewById()都是父容器找子控件，被include的 layout里的控件要在都位于主layout中，所以要用 主layout对应的view.findViewById()才能找到子layout中的控件。

Caution:

　　If you want to override layout attributes using the <include> tag, you must override both android:layout_height and android:layout_width in order for other layout attributes to take effect.

　　Another way to include a layout is to use ViewStub. It is a lightweight View that consumes no layout space until you explicitly inflate it, at which point, it includes a layout file defined by itsandroid:layout attribute. For more information about using ViewStub, read Loading Views On Demand.

示例：

主layout: frgmt_main.xml

 　　<FrameLayout
                 android:id="@android:id/tabcontent"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent">

                 <!-- tab1,用include可以引用别处的layout -->
                 <include
                     android:id="@+id/tab_weixin"

                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
                     layout="@layout/tab_weixin_layout" />

被include的layout ：  tab_weixin_layout.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:id="@+id/tab_weixin_layout"
     android:orientation="vertical" >
     <LinearLayout
         android:id="@+id/tab_weixin_qq_friend"
         android:layout_width="match_parent"
         android:orientation="horizontal"
         android:layout_height="wrap_content" >

         <ImageView
             android:id="@+id/iv_tab_weixin_qq_friend"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:scaleType="centerInside"
             android:src="@drawable/tab_weixin_qq_scale" />

         <TextView
             android:id="@+id/tv_tab_weixin_qq_friend"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/find_qq_friends" />

     </LinearLayout>

     <ListView
         android:id="@+id/tab_weixin_list"
         android:layout_width="match_parent"
         android:layout_height="match_parent" >
     </ListView>

 </LinearLayout>