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我有一个播放音乐的服务和一个提供与服务交互的 GUI 的活动。活动在列表项单击时打开(我有一个录音列表),它在 onCreate() 方法绑定服务(并创建它) .

调用 onDestroy() 时,我取消绑定服务(这将破坏服务) - 这应该没问题,因为如果退出活动,我不希望服务运行,但问题出现在方向更改上,因为它重新创建再次活动和服务(旋转设备时,曲目停止并从头开始播放)。

我知道一些可能有用的标志(orientationChange),但对我来说不是一个好习惯,因为我想要一个不同的横向布局。只要我的应用程序运行,我也可以让音乐播放器服务运行,但这不是一个好主意,因为用户可能不想打开播放器,而只想录制,所以播放器服务不一定在这里.

以下是一些代码片段:

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        LocalBroadcastManager.getInstance(this).registerReceiver(mLocalReceiver, new IntentFilter(PlayerBroadcastReceiver.ACTION_PLAYER_SERVICE_STARTED));
        setContentView(R.layout.media_player_screen);
        setVolumeControlStream(AudioManager.STREAM_MUSIC);
        AudioPlayerServiceBridge.getInstance().addCallback(this);
        AudioPlayerServiceBridge.getInstance().doBindService(this);

        init(savedInstanceState);       
        super.onCreate(savedInstanceState);
    }

@Override
protected void onDestroy() {
    LocalBroadcastManager.getInstance(this).unregisterReceiver(mLocalReceiver);
    mLocalReceiver.removeCallback();
    Log.d(AudioPlayerActivity.class.getName(), "onDestroy() -> "+AudioPlayerActivity.class.getName());
    AudioPlayerServiceBridge.getInstance().doUnbindService(this);
    AudioPlayerServiceBridge.getInstance().removeCallback(this);

    super.onDestroy();
}

和服务连接管理器:

public void doBindService(Context context) {
    // Establish a connection with the service.  We use an explicit
    // class name because there is no reason to be able to let other
    // applications replace our component.
    if(!mIsBound){
        context.bindService(new Intent(context, 
                AudioPlayerService.class), serviceConnection, Context.BIND_AUTO_CREATE);
        mIsBound = true;
    }
}

public void doUnbindService(Context context) {
    if (mIsBound) {
        // If we have received the service, and hence registered with
        // it, then now is the time to unregister.
        if (mServiceMessenger != null) {
            Message msg = Message.obtain(null, AudioPlayerService.MSG_UNREGISTER_CLIENT);
            msg.replyTo = mMessenger;
            mServiceMessenger.send(msg);
        }

        // Detach our existing connection.
        context.unbindService(serviceConnection);
        mIsBound = false;
    }
}

如果可能的话,请告诉我一个处理这个问题的好习惯。

4

1 回答 1

2

答案是:

我应该使用以下命令启动服务: startService(new Intent(this, service.class)) 并在此之后开始绑定。此方法可防止在调用 doUnbind() 时终止服务。因此 onCreate() 方法现在更改为:

@Override
protected void onCreate(Bundle savedInstanceState) {
    LocalBroadcastManager.getInstance(this).registerReceiver(mLocalReceiver, new IntentFilter(PlayerBroadcastReceiver.ACTION_PLAYER_SERVICE_STARTED));
    setContentView(R.layout.media_player_screen);
    setVolumeControlStream(AudioManager.STREAM_MUSIC);

    if(savedInstanceState == null)
        startService(new Intent(this, AudioPlayerService.class));

    AudioPlayerServiceBridge.getInstance().addCallback(this);
    AudioPlayerServiceBridge.getInstance().doBindService(this);

    init(savedInstanceState);       
    super.onCreate(savedInstanceState);
}

onDestroy() 方法:

@Override
    protected void onDestroy() {
        LocalBroadcastManager.getInstance(this).unregisterReceiver(mLocalReceiver);
        mLocalReceiver.removeCallback();
        Log.d(AudioPlayerActivity.class.getName(), "onDestroy() -> "+AudioPlayerActivity.class.getName());
        AudioPlayerServiceBridge.getInstance().doUnbindService(this);
        AudioPlayerServiceBridge.getInstance().removeCallback(this);

        super.onDestroy();
    }

并在 onBackPressed() 中停止服务(如果需要):

@Override
public void onBackPressed() {
    Log.d(AudioPlayerActivity.class.getName(), "onBackPressed() -> "+AudioPlayerActivity.class.getName());
    isPaused = true;
    Log.d(AudioPlayerActivity.class.getName(), "Sending message to player service: MSG_RELEASE_PLAYER");
    AudioPlayerServiceBridge.getInstance().sendAsyncCall(AudioPlayerService.MSG_RELEASE_PLAYER);

    if(mSeekBarChanger != null){
        mSeekBarChanger.stopThread();
    }       

    AudioPlayerServiceBridge.getInstance().doUnbindService(this);
    stopService(new Intent(this, AudioPlayerService.class));
    super.onBackPressed();      
}
于 2013-06-04T09:53:41.393 回答