android - 我如何知道我的应用程序是否已最小化？

Question

Activity.onPause() 和 onStop() 在(至少)两种情况下被调用:

1. 另一个 Activity 在当前 Activity 之上启动。
2. 该应用已最小化。

有没有简单的方法来区分？

Answer 1

你可以这样做。让您的所有 Activity 都从基础 Activity 延伸出来。基本 Activity 需要保留一个可见性计数器，该计数器在 onResume/onPause 期间递增/递减:

public abstract class MyBaseActivity extends ActionBarActivity {
    private static int visibility = 0;
    private Handler handler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        handler = new Handler();
    }

    @Override
    protected void onResume() {
        super.onResume();
        visibility++;
        handler.removeCallBacks(pauseAppRunnable);
    }

    @Override
    protected void onPause() {
        super.onPause();
        visibility--;
        handler.removeCallBacks(pauseAppRunnable);
        // give a short delay here to account for the overhead of starting
        // a new activity. Might have to tune this a bit (not tested).
        handler.postDelayed(pauseAppRunnable, 100L);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // uncomment this if you want the app to NOT respond to invisibility 
        // if the user backed out of all open activities.
        //handler.removeCallBacks(pauseAppRunnable);
    }

    private Runnable pauseAppRunnable = new Runnable() {
        @Override
        public void run() {
            if (visibility == 0) {
                // do something about it
            }
        }
    };

}