最近学习了android的布局样式标签，布局样式标签一共有5个，感觉FrameLayout和RelativeLayout最为灵活，而FrameLayout就像web中iframe框架一样，是一个框架布局样式，可以用include标签载入定义的另一个layout文件，现在用一个ProgressBar的例子学习一下 FrameLayout。（文/huangbq）首先，我们创建一个布局文件,res/layout/fullscreen_loading.xml, 其内容如下:
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:gravity="center_vertical|center_horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent android:id="@+id/fullscreen_loading" android:visibility="gone" > <ProgressBar android:layout_gravity="center_vertical" android:layout_width="wrap_content" android:layout_height="wrap_content" style="?android:attr/progressBarStyleSmall" > </ProgressBar> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="5.0dip" android:text="loading..." > </TextView></LinearLayout> 然后在main.xml 把它include 进来 <?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" > <LinearLayout android:orientation="vertical" android:visibility="gone" android:layout_width="fill_parent" android:layout_height="fill_parent" > </LinearLayout> <include android:visibility="visible" android:layout_width="fill_parent" android:layout_height="fill_parent" layout="@layout/fullscreen_loading" > </include></FrameLayout> 主程序 LoadingActivity.java: package com.google.android.test;import android.app.Activity;import android.os.Bundle;import android.widget.LinearLayout;public class LoadingActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }}