Android_按兩次返回鍵退出程序和長按返回鍵退出程序

以上兩個功能主要是參考了一下博客的:

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序:

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(), "再按一次退出程序", Toast.LENGTH_SHORT).show(); exit.doExitInOneSecond(); } } } 

輔助類Exit.java

private boolean isExit = false;  
private Runnable task = new Runnable() {  
    @Override  
    public 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;  
}  

 

 

長按返回鍵退出程序:

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：

private long exitTime = 0; 

 

@Override 

public boolean onKeyDown(int keyCode, KeyEvent event) { 

if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){ 

if((System.currentTimeMillis()-exitTime) > 2000){ 

Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show(); 

exitTime = System.currentTimeMillis(); 

} else { 

finish(); 

System.exit(0); 

} 

return true; 

} 

return super.onKeyDown(keyCode, event); 

}