将服务从一项活动传递到另一项活动

如何将服务从一项活动传递到另一项活动？我有一个音乐播放器 (Activity1)，它显示歌曲列表，当您单击它时，它会启动 Activity1 中的服务。我有一个按钮，用户可以单击该按钮来打开 Activity2。

那么我将服务从 Activity1 传递到 Activity2 的最佳方式是什么？如果服务在 Activity1 中启动，那么 Activity2 应该继续播放。如果Activity1中没有启动该服务，那么Activity2应该在使用该服务之前启动该服务。

Thanks.

下面是一些示例代码，MusicService 是一个扩展服务类的类。

 public class Activity1 extends AppCompatActivity {

 private MusicService serviceMusic;  

private ServiceConnection musicConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder service) {
        MusicService.PlayerBinder binder = (MusicService.PlayerBinder) service;
        //get service
        serviceMusic = binder.getService();
        serviceMusic.setSongList(songList);
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {

    }
};

}

我认为最好bind服务而不是pass a 静态全局服务。由于您有多个将使用相同服务的活动，因此应像这样创建一个基本活动：

基本服务活动.java

public abstract class BasicServiceActivity extends AppCompatActivity {
    protected DvrService mDvrService;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_basic);
        attachService();
    }

    @Override
    protected void onDestroy() {
        detachService();
        super.onDestroy();
    }

    private ServiceConnection mServiceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder binder) {
            DvrService.DvrServiceBinder serviceBinder = (DvrService.DvrServiceBinder) binder;
            mDvrService = serviceBinder.getService();
            onServiceAttached(mDvrService);
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            mDvrService = null;
        }
    };

    private void attachService() {
        Intent service = new Intent(this, DvrService.class);
        bindService(service, mServiceConnection, Service.BIND_AUTO_CREATE);
    }

    private void detachService() {
        unbindService(mServiceConnection);
    }

    /** Callback when service attached. */
    protected void onServiceAttached(DvrService service) {
        // do something necessary by its subclass.
    }
}

然后你可以像这样实现子类活动：

public class ServiceActivity extends BasicServiceActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        startService(new Intent(this, DvrService.class));
    }

    @Override
    protected void onDestroy() {
        if (mDvrService != null) {
            mDvrService.removeListener1(mListener1);
        }
        super.onDestroy();
    }

    @Override
    protected void onServiceAttached(DvrService service) {
        // do your stuff, for example add a listener.
        service.addListener1(mListener1);
    }
}