Android布局学习——线性布局和相对布局混合使用

<? xml version="1.0" encoding="utf-8" ?>
< LinearLayout  xmlns:android ="http://schemas.android.com/apk/res/android"
    android:orientation ="vertical"  android:layout_width ="fill_parent"
    android:layout_height ="fill_parent" >
     < RelativeLayout  android:layout_width ="fill_parent"
        android:layout_height ="wrap_content" >
         < Button  android:id ="@+id/BtnGo"  android:layout_width ="wrap_content"
            android:layout_height ="wrap_content"  android:layout_alignParentRight ="true"
            android:text ="Go" ></ Button >         
         < EditText  android:id ="@+id/TextUrl"  android:layout_width ="fill_parent"
            android:layout_height ="wrap_content"  android:hint ="请输入网址"
            android:layout_alignTop ="@id/BtnGo"  android:layout_toLeftOf ="@id/BtnGo" ></ EditText >
     </ RelativeLayout >
     < WebView  android:id ="@+id/WebView01"  android:layout_width ="fill_parent"
        android:layout_height ="fill_parent" >         
     </ WebView >
</ LinearLayout >