android onKeyDown(int keyCode, KeyEvent event)

  
    

   
      1 
   
     @Override

   
      2 
   
      
   
     public
   
      
   
     boolean
   
      onKeyDown(
   
     int
   
      keyCode, KeyEvent event) {

   
      3 
   
      
   
     //
   
      TODO Auto-generated method stub
   
     

   
      4 
   
     
   
      

   
      5 
   
      
   
     if
   
     (keyCode
   
     ==
   
     KeyEvent.KEYCODE_BACK){

   
      6 
   
      
   
     //
   
     弹出确定退出对话框
   
     

   
      7 
   
     
   
      
   
     new
   
      AlertDialog.Builder(
   
     this
   
     )

   
      8 
   
      .setTitle(
   
     "
   
     退出
   
     "
   
     )

   
      9 
   
      .setMessage(
   
     "
   
     确定退出吗？
   
     "
   
     )

   
     10 
   
      .setPositiveButton(
   
     "
   
     确定
   
     "
   
     , 
   
     new
   
      DialogInterface.OnClickListener() {

   
     11 
   
      

   
     12 
   
      @Override

   
     13 
   
      
   
     public
   
      
   
     void
   
      onClick(DialogInterface dialog, 
   
     int
   
      which) {

   
     14 
   
      
   
     //
   
      TODO Auto-generated method stub
   
     

   
     15 
   
     
   
      Intent exit 
   
     =
   
      
   
     new
   
      Intent(Intent.ACTION_MAIN);

   
     16 
   
      exit.addCategory(Intent.CATEGORY_HOME);

   
     17 
   
      exit.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

   
     18 
   
      startActivity(exit);

   
     19 
   
      System.exit(
   
     0
   
     );

   
     20 
   
      }

   
     21 
   
      })

   
     22 
   
      .setNegativeButton(
   
     "
   
     取消
   
     "
   
     , 
   
     new
   
      DialogInterface.OnClickListener() {

   
     23 
   
      

   
     24 
   
      @Override

   
     25 
   
      
   
     public
   
      
   
     void
   
      onClick(DialogInterface dialog, 
   
     int
   
      which) {

   
     26 
   
      
   
     //
   
      TODO Auto-generated method stub
   
     

   
     27 
   
     
   
      dialog.cancel();

   
     28 
   
      }

   
     29 
   
      })

   
     30 
   
      .show();

   
     31 
   
      
   
     //
   
     这里不需要执行父类的点击事件，所以直接return
   
     

   
     32 
   
     
   
      
   
     return
   
      
   
     true
   
     ;

   
     33 
   
      }

   
     34 
   
      
   
     //
   
     继续执行父类的其他点击事件
   
     

   
     35 
   
     
   
      
   
     return
   
      
   
     super
   
     .onKeyDown(keyCode, event);

   
     36 
   
      }