1. 设置屏幕方向

横向和竖向切换：

  1. if(getRequestedOrientation() == ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE){ 
  2.                     setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT); 
  3.                 }else { 
  4.                     setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); 
  5.                 } 


可设置activity默认方向：


  1. <activity android:name=".ActivityMain" 
  2.                   android:label="@string/app_name" 
  3.                   android:screenOrientation="landscape"> 


2.设置activity属性


使activity为一个窗口：


  1. android :theme="@android:style/Theme.Dialog" 


使activity透明：


  1. android:theme="@android:style/Theme.Translucent" 


使activity全屏：


  1. android:theme="@android:style/Theme.NoTitleBar.Fullscreen" 


3. activity被系统回收时，保存数据


  1. @Override 
  2.     protected void onSaveInstanceState(Bundle outState) { 
  3.         outState.putInt("id",123); 
  4.         super.onSaveInstanceState(outState); 
  5.     } 


再次启动时可获取数值


  1. @Override 
  2.     public void onCreate(Bundle savedInstanceState) { 
  3.         super.onCreate(savedInstanceState); 
  4.         if(savedInstanceState != null){ 
  5.             System.out.println(savedInstanceState.getInt("id")); 
  6.         } 
  7.         setContentView(R.layout.main); 
  8.     }