Android初級教程_按兩次返回鍵退出程式和長按返回鍵退出程式

以上兩個功能主要是參考了一下部落格的:

http://blog.csdn.net/chenshijun0101/article/details/7682210

http://blog.csdn.net/winlinking/article/details/6596455

方法一：

按兩次返回鍵退出程式:

public class Exit {

private boolean isExit = false;private Runnable task = new Runnable() {@Overridepublic void run() {isExit = false;}};public void doExitInOneSecond() {isExit = true;HandlerThread thread = new HandlerThread("doTask");thread.start();new Handler(thread.getLooper()).postDelayed(task, 1000);}public boolean isExit() {return isExit;}public void setExit(boolean isExit) {this.isExit = isExit;}}

Activity:

public class Back2FinishAppActivity extends Activity {Exit exit = new Exit();    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);    }                @Override        public boolean onKeyDown(int keyCode, KeyEvent event) {          if (keyCode == KeyEvent.KEYCODE_BACK) {                  pressAgainExit();                  return true;                  }                return super.onKeyDown(keyCode, event);        }            private void pressAgainExit() {              if (exit.isExit()) {                  finish();              } else {                  Toast.makeText(getApplicationContext(), "再按一次退出程式",                          Toast.LENGTH_SHORT).show();                  exit.doExitInOneSecond();              }          }  }

長按返回鍵退出程式:

public boolean dispatchKeyEvent(KeyEvent event)      {          int keyCode=event.getKeyCode();          switch(keyCode)          {              case KeyEvent.KEYCODE_BACK: {                   if(event.isLongPress())                   {                       this.stopService(intent);                       System.exit(0);                       return true;                   }else                   {                       return false;                       }              }            }          return super.dispatchKeyEvent(event);                }

方法二：

1. private long exitTime = 0; 
2.  
3. @Override 
4. public boolean onKeyDown(int keyCode, KeyEvent event) { 
5. if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){ 
6. if((System.currentTimeMillis()-exitTime) > 2000){ 
7. Toast.makeText(getApplicationContext(), "再按一次退出程式", Toast.LENGTH_SHORT).show(); 
8. exitTime = System.currentTimeMillis(); 
9. } else { 
10. finish(); 
11. System.exit(0); 
12. } 
13. return true; 
14. } 
15. return super.onKeyDown(keyCode, event); 
16. } 

歡迎轉載:http://blog.csdn.net/johnny901114/article/details/7823048