android - 如何在用户滑动应用程序后继续在后台播放音乐？

Question

在 Android 中，我使用 Service 和 MediaPlayer 来播放音乐。当我按下主页按钮时，音乐会继续播放，但如果我“滑开”应用程序，音乐就会停止。

How could I continue music playing after swiping away the app?

Answer 1

您需要使用 Service.START_STICKY :

public int onStartCommand(Intent intent, int flags, int startId) {
    mediaPlayer.start();
    return Service.START_STICKY;
}

Service.START_STICKY : if this service's process is killed while it is started the system will try to re-create the service.

这是一个完整的例子: https://github.com/Jorgesys/Android-Music-in-Background

public class BackgroundSoundService extends Service {

    private static final String TAG = "BackgroundSoundService";
    MediaPlayer player;

    public IBinder onBind(Intent arg0) {
        Log.i(TAG, "onBind()" );
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        player = MediaPlayer.create(this, R.raw.jorgesys_song);
        player.setLooping(true); 
        player.setVolume(100, 100);
        Toast.makeText(this, "Service started...", Toast.LENGTH_SHORT).show();
        Log.i(TAG, "onCreate() , service started...");

    }
    public int onStartCommand(Intent intent, int flags, int startId) {
        player.start();
        return Service.START_STICKY;
    }

    public IBinder onUnBind(Intent arg0) {
        Log.i(TAG, "onUnBind()");
        return null;
    }

    public void onStop() {
        Log.i(TAG, "onStop()");
    }
    public void onPause() {
        Log.i(TAG, "onPause()");
    }
    @Override
    public void onDestroy() {
        player.stop();
        player.release();
        Toast.makeText(this, "Service stopped...", Toast.LENGTH_SHORT).show();
        Log.i(TAG, "onCreate() , service stopped...");
    }

    @Override
    public void onLowMemory() {
        Log.i(TAG, "onLowMemory()");
    }
}