安卓点击两次返回键退出程序

 1     private void exit() {
 2         if (!isExit) {
 3             isExit = true;
 4             Toast.makeText(getApplicationContext(), "再按一次退出程序",
 5                     Toast.LENGTH_SHORT).show();
 6             // 利用handler延迟发送更改状态信息
 7             mHandler.sendEmptyMessageDelayed(0, 2000);
 8         } else {
 9             Utils.logout(WalkMainActivity.this);
10             Utils.disableBluetooth(this);
11             finish();
12             System.exit(0);
13            // android.os.Process.killProcess(android.os.Process.myPid()) ;
14         }
15     }

 1 @Override
 2     public boolean onKeyDown(int keyCode, KeyEvent event) {
 3         if (keyCode == KeyEvent.KEYCODE_BACK) {
 4             Utils.hiddenProgram(getApplicationContext());
 5         }
 6         if (keyCode == KeyEvent.KEYCODE_MENU) {
 7             drawerUtil.openCloseDrawerLayout();
 8         }
 9         return super.onKeyDown(keyCode, event);
10     }