按两次返回键退出程序和长按返回键退出程序

按两次返回键退出程序:

public class Exit {

[java]  view plain copy

1. private boolean isExit = false;  
2. private Runnable task = new Runnable() {  
3.     @Override  
4.     public void run() {  
5.         isExit = false;  
6.     }  
7. };  
8. public void doExitInOneSecond() {  
9.     isExit = true;  
10.     HandlerThread thread = new HandlerThread("doTask");  
11.     thread.start();  
12.     new Handler(thread.getLooper()).postDelayed(task, 1000);  
13. }  
14. public boolean isExit() {  
15.     return isExit;  
16. }  
17. public void setExit(boolean isExit) {  
18.     this.isExit = isExit;  
19. }  

Activity:

[java]  view plain copy

1. public class Back2FinishAppActivity extends Activity {  
2.     Exit exit = new Exit();  
3.     @Override  
4.     public void onCreate(Bundle savedInstanceState) {  
5.         super.onCreate(savedInstanceState);  
6.         setContentView(R.layout.main);  
7.     }  
8.     @Override    
9.       public boolean onKeyDown(int keyCode, KeyEvent event) {    
10.         if (keyCode == KeyEvent.KEYCODE_BACK) {    
11.                 pressAgainExit();    
12.                 return true;    
13.                 }    
14.           return super.onKeyDown(keyCode, event);    
15.       }    
16.     private void pressAgainExit() {    
17.             if (exit.isExit()) {    
18.                 finish();    
19.             } else {    
20.                 Toast.makeText(getApplicationContext(), "再按一次退出程序",    
21.                         Toast.LENGTH_SHORT).show();    
22.                 exit.doExitInOneSecond();    
23.             }    
24.         }    
25. }  

长按返回键退出程序:

[java]  view plain copy

1. public boolean dispatchKeyEvent(KeyEvent event)    
2.     {    
3.         int keyCode=event.getKeyCode();    
4.         switch(keyCode)    
5.         {    
6.             case KeyEvent.KEYCODE_BACK: {    
7.                  if(event.isLongPress())    
8.                  {    
9.                      this.stopService(intent);    
10.                      System.exit(0);    
11.                      return true;    
12.                  }else    
13.                  {    
14.                      return false;    
15.                  }    
16.             }      
17.         }    
18.         return super.dispatchKeyEvent(event);    
19.     }