Android连续点击两次Back键退出程序

Android连续点击两次Back键退出程序       

        分类：            Android2012-11-29 14:17288人阅读评论(0)收藏举报

     思路1：记录上次点击的时间，与本次点击的时间比较，当两次时间间隔小于一定值时，退出，否则提示“再按一次退出程序”，同时更新上次点击时间

   

[java] view plaincopyprint?

1. private long firstTime =0; 
2.    @Override 
3. public boolean onKeyUp(int keyCode, KeyEvent event) { 
4.        // TODO Auto-generated method stub 
5.        switch(keyCode) 
6.        { 
7.        case KeyEvent.KEYCODE_BACK: 
8.             long secondTime = System.currentTimeMillis();  
9.              if (secondTime - firstTime >2000) {                                        //如果两次按键时间间隔大于2秒，则不退出 
10.                  Toast.makeText(this,"再按一次退出程序", Toast.LENGTH_SHORT).show();  
11.                  firstTime = secondTime;//更新firstTime 
12.                  return true;  
13.              } else {                                                   //两次按键小于2秒时，退出应用 
14.             System.exit(0); 
15.              }  
16.            break; 
17.        } 
18.      return super.onKeyUp(keyCode, event); 
19.    } 

 private long firstTime = 0;    @Override public boolean onKeyUp(int keyCode, KeyEvent event) {        // TODO Auto-generated method stub        switch(keyCode)        {        case KeyEvent.KEYCODE_BACK:             long secondTime = System.currentTimeMillis();               if (secondTime - firstTime > 2000) {                                         //如果两次按键时间间隔大于2秒，则不退出                  Toast.makeText(this, "再按一次退出程序", Toast.LENGTH_SHORT).show();                   firstTime = secondTime;//更新firstTime                  return true;               } else {                                                    //两次按键小于2秒时，退出应用             System.exit(0);              }             break;        }      return super.onKeyUp(keyCode, event);    }

     思路2：开线程延时处理

[java] view plaincopyprint?

1. private int mBackKeyPressedTimes =0; 
2.  
3.         @Override 
4.         public void onBackPressed() { 
5.                 if (mBackKeyPressedTimes ==0) { 
6.                         Toast.makeText(this,"再按一次退出程序 ", Toast.LENGTH_SHORT).show(); 
7.                         mBackKeyPressedTimes = 1; 
8.                         new Thread() { 
9.                                 @Override 
10.                                 publicvoid run() { 
11.                                         try { 
12.                                                 Thread.sleep(2000); 
13.                                         } catch (InterruptedException e) { 
14.                                                 e.printStackTrace(); 
15.                                         } finally { 
16.                                                 mBackKeyPressedTimes = 0; 
17.                                         } 
18.                                 } 
19.                         }.start(); 
20.                         return; 
21.                       else{ 
22.                                this.activity.finish(); 
23.                             } 
24.                 } 
25.                 super.onBackPressed(); 
26.         }