你的位置:首页 > 操作系统

[操作系统]按二次返回键退出


  @Override  public boolean onKeyDown(int keyCode, KeyEvent event) {    if (keyCode == KeyEvent.KEYCODE_BACK) {      exit();      return false;    }    return super.onKeyDown(keyCode, event);  }  private long exitTime = 0;  public void exit() {    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);    }  }