再按一次返回键退出最终完整方案:
boolean isExit;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyApplication.getInstance().addActivity(this);
}
@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK) {// 再按一次退出 exit();return false;} else {return super.onKeyDown(keyCode, event);}}private void exit() {if (!isExit) {isExit = true;Toast.makeText(getApplicationContext(), "再按一次退出程序",Toast.LENGTH_SHORT).show();mHandler.sendEmptyMessageDelayed(0, 2000);} else {MyApplication.getInstance().exit();}}Handler mHandler = new Handler() {@Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubsuper.handleMessage(msg);isExit = false;}};
完整退出:
之前的退出方案,经常会退出不完全。
Intent intent = new Intent(Intent.ACTION_MAIN);intent.addCategory(Intent.CATEGORY_HOME);startActivity(intent);System.exit(0);
替代方案:
一种比较流行的Android经典完美退出方法,使用单例模式创建一个Activity管理对象,该对象中有一个Activity容器(具体实现自己处理,使用LinkedList等)专门负责存储新开启的每一个Activity,并且容易理解、易于操作,非常不错!MyApplication类(储存每一个Activity,并实现关闭所有Activity的操作)
public class MyApplication extends Application {private List<Activity> activityList = new LinkedList<Activity>(); private static MyApplication instance;private MyApplication(){}//单例模式中获取唯一的MyApplication实例 public static MyApplication getInstance(){if(null == instance){instance = new MyApplication();}return instance; }//添加Activity到容器中public void addActivity(Activity activity){activityList.add(activity);}//遍历所有Activity并finishpublic void exit(){for(Activity activity:activityList){activity.finish();}System.exit(0);}}
在每一个Activity中的onCreate方法里添加该Activity到MyApplication对象实例容器中MyApplication.getInstance().addActivity(this);在需要结束所有Activity的时候调用exit方法MyApplication.getInstance().exit();