在媒体按钮接收器中获取非法参数异常

Question

我正在尝试在我的服务中播放歌曲，并且我能够在棒棒糖及以上设备上成功播放它。我看到一些教程，它表明使用 classname 方法我们可以为棒棒糖设备执行此操作，这就是我得到的错误

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start service beatbox.neelay.beatbox.MediaService@41e92b60 with Intent { cmp=beatbox.neelay.beatbox/.MediaService }: java.lang.IllegalArgumentException: MediaButtonReceiver component may not be null.
  at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2510)
  at android.app.ActivityThread.access$1900(ActivityThread.java:133)
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1295)
  at android.os.Handler.dispatchMessage(Handler.java:99)
  at android.os.Looper.loop(Looper.java:137)
  at android.app.ActivityThread.main(ActivityThread.java:4793)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:511)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:808)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:575)
  at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException: MediaButtonReceiver component may not be null.
  at android.support.v4.media.session.MediaSessionCompat$MediaSessionImplBase.<init>(MediaSessionCompat.java:1507)
  at android.support.v4.media.session.MediaSessionCompat.<init>(MediaSessionCompat.java:278)
  at beatbox.neelay.beatbox.MediaService.initMediaSession(MediaService.java:660)
  at beatbox.neelay.beatbox.MediaService.onStartCommand(MediaService.java:172)
  at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2493)
  at android.app.ActivityThread.access$1900(ActivityThread.java:133) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1295) 
  at android.os.Handler.dispatchMessage(Handler.java:99) 
  at android.os.Looper.loop(Looper.java:137) 
  at android.app.ActivityThread.main(ActivityThread.java:4793) 
  at java.lang.reflect.Method.invokeNative(Native Method) 
  at java.lang.reflect.Method.invoke(Method.java:511) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:808) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:575) 
  at dalvik.system.NativeStart.main(Native Method) 

07

这就是我调用服务的方式 在主活动绑定部分

private ServiceConnection serviceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
// We've bound to LocalService, cast the IBinder and get LocalService instance
MediaService.LocalBinder binder = (MediaService.LocalBinder) service;
MainActivity.this.player = binder.getService();
serviceBound = true;
}
@Override
public void onServiceDisconnected(ComponentName name) {
serviceBound = false;
}
};

这就是我调用服务的方式

Intent playerIntent = new Intent(getApplicationContext(), MediaService.class);
playerIntent.setAction(Constants.ACTION.STARTFOREGROUND_ACTION);
startService(playerIntent);
bindService(playerIntent, serviceConnection, Context.BIND_AUTO_CREATE);

这是我的媒体会话方法，我收到错误

private void initMediaSession() throws RemoteException {
if (mediaSessionManager != null)  //mediaSessionManager exists
mediaSessionManager  = new ComponentName(getApplicationContext(), MediaButtonReceiver.class);
// Create a new MediaSession
mediaSession = new MediaSessionCompat(getApplicationContext(), "Tag", mediaSessionManager, null);
//Get MediaSessions transport controls
transportControls = mediaSession.getController().getTransportControls();
//set MediaSession -> ready to receive media commands
mediaSession.setActive(true);
//indicate that the MediaSession handles transport control commands
// through its MediaSessionCompat.Callback.
mediaSession.setFlags(MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
Intent mediaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
mediaButtonIntent.setClass(this, MediaButtonReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, mediaButtonIntent, 0);
mediaSession.setMediaButtonReceiver(pendingIntent);

该应用程序在安卓M上正常运行，但它为安卓软糖豆显示此错误

Answer 1

您应该在清单.xml文件中声明一个MediaButtonReceiver，该文件将所有媒体按钮键委托给MediaSession服务

<receiver android:name="android.support.v4.media.session.MediaButtonReceiver" >
<intent-filter>
<action android:name="android.intent.action.MEDIA_BUTTON" />
</intent-filter>
</receiver>

更多在这里 https://developer.android.com/reference/android/support/v4/media/session/MediaButtonReceiver.html

和这里

https://developer.android.com/guide/topics/media-apps/mediabuttons.html