@Override 
ic void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
/**全屏设置，隐藏窗口所有装饰**/ 
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
    WindowManager.LayoutParams.FLAG_FULLSCREEN); 
/**标题是属于View的，所以窗口所有的修饰部分被隐藏后标题依然有效,需要去掉标题**/ 
requestWindowFeature(Window.FEATURE_NO_TITLE); 
setContentView(R.layout.main); 

<activity 
 android:name=".ActivityDemo" 
 android:label="@string/app_name" 
 android:theme="@android:style/Theme.NoTitleBar"> 
<intent-filter> 
    <action android:name="android.intent.action.MAIN" /> 
    <category android:name="android.intent.category.LAUNCHER" /> 
</intent-filter> 
 </activity> 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" 
  android:background="@drawable/welcome" 
  android:orientation="vertical" > 
</LinearLayout>