Android RemoteController使用

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转载最新推荐文章于 2026-07-04 08:21:55 发布 3.5k 阅读 AI 写同款· GEO 优化 ›

写一个APP控制第三方播放器播放，以及获取正在播放的歌曲信息最近遇到这么一个需求，就是在自己的应用中控制第三方播放器播放，以及获取正在播放的歌曲信息，包括名字，歌手，专辑，显示出来。一开始觉得很简单，但实际上遇到了不少的麻烦，最终实现了两种方案，读者可根据自己需要选择。阅读详情

RemoteController在API 19 引进，用来给音乐控制提供标准接口。长久以来，音乐播放在Android平台没有一个标准的接口，所有播放器都使用自己的方式实现对音乐的控制，最常见的方式是在Service中进行音乐播放，通过PendingIntent进行播放事件的传递及控制，因此就带来了一个问题。任何一个第三方app无法通过标准方式获取到当前正在播放的音乐的信息，更无法进行控制。RemoteController的出现恰好解决了这个问题，RemoteController需要和RemoteControlClient配合使用，从命名上能够看出，RemoteController是控制及信息获取端的接口，用来进行音乐信息的获取以及音乐播放动作的发送。RemoteControlClient是播放器端的接口，用来获取并执行播放动作，同时讲当前播放状态信息进行同步。

1.继承 NotificationListenerService 并实现RemoteController.OnClientUpdateListener接口来创建remoteController对象并获取播放进度

  @TargetApi(Build.VERSION_CODES.KITKAT)
public class MusicStateListener extends NotificationListenerService
    implements RemoteController.OnClientUpdateListener {
}

NotificationListenerService的主要作用是用来获取和操作通知栏通知，由于很奇葩的原因，为了获取合法的remoteController对象，必须实现这样一个NotificationListenerService并作为onClientUpdateListener传入remoteController来实现。

    public void registerRemoteController() {
        remoteController = new RemoteController(this, this);
        boolean registered;
        try {
          registered = ((AudioManager) getSystemService(AUDIO_SERVICE))
              .registerRemoteController(remoteController);
        } catch (NullPointerException e) {
          registered = false;
    }
    if (registered) {
      try {
        remoteController.setArtworkConfiguration(
            getResources().getDimensionPixelSize(R.dimen.remote_artwork_bitmap_width),
            getResources().getDimensionPixelSize(R.dimen.remote_artwork_bitmap_height));
        remoteController.setSynchronizationMode(RemoteController.POSITION_SYNCHRONIZATION_CHECK);
      } catch (IllegalArgumentException e) {
        e.printStackTrace();
      }
    }
  }

RemoteController的初始化传入的两个参数分别是context和updateListener，而且此处的context必须是notificationListenerService

2.获取播放信息

合法register之后在回调中会接收到播放信息，包括播放/暂停等动作信息以及歌曲的meta信息

/**
 * Interface definition for the callbacks to be invoked whenever media events, metadata
 * and playback status are available.
 */
public interface OnClientUpdateListener {
    /**
     * Called whenever all information, previously received through the other
     * methods of the listener, is no longer valid and is about to be refreshed.
     * This is typically called whenever a new {@link RemoteControlClient} has been selected
     * by the system to have its media information published.
     * @param clearing true if there is no selected RemoteControlClient and no information
     *     is available.
     */
    public void onClientChange(boolean clearing);

    /**
     * Called whenever the playback state has changed.
     * It is called when no information is known about the playback progress in the media and
     * the playback speed.
     * @param state one of the playback states authorized
     *     in {@link RemoteControlClient#setPlaybackState(int)}.
     */
    public void onClientPlaybackStateUpdate(int state);
    /**
     * Called whenever the playback state has changed, and playback position
     * and speed are known.
     * @param state one of the playback states authorized
     *     in {@link RemoteControlClient#setPlaybackState(int)}.
     * @param stateChangeTimeMs the system time at which the state change was reported,
     *     expressed in ms. Based on {@link android.os.SystemClock#elapsedRealtime()}.
     * @param currentPosMs a positive value for the current media playback position expressed
     *     in ms, a negative value if the position is temporarily unknown.
     * @param speed  a value expressed as a ratio of 1x playback: 1.0f is normal playback,
     *    2.0f is 2x, 0.5f is half-speed, -2.0f is rewind at 2x speed. 0.0f means nothing is
     *    playing (e.g. when state is {@link RemoteControlClient#PLAYSTATE_ERROR}).
     */
    public void onClientPlaybackStateUpdate(int state, long stateChangeTimeMs,
            long currentPosMs, float speed);
    /**
     * Called whenever the transport control flags have changed.
     * @param transportControlFlags one of the flags authorized
     *     in {@link RemoteControlClient#setTransportControlFlags(int)}.
     */
    public void onClientTransportControlUpdate(int transportControlFlags);
    /**
     * Called whenever new metadata is available.
     * See the {@link MediaMetadataEditor#putLong(int, long)},
     *  {@link MediaMetadataEditor#putString(int, String)},
     *  {@link MediaMetadataEditor#putBitmap(int, Bitmap)}, and
     *  {@link MediaMetadataEditor#putObject(int, Object)} methods for the various keys that
     *  can be queried.
     * @param metadataEditor the container of the new metadata.
     */
    public void onClientMetadataUpdate(MetadataEditor metadataEditor);
};

音乐的meta信息从onClientMetadataUpdate回调中获取，能够获取到的字段包括歌手、名称、专辑名称、专辑封面等。注意此处获取到的专辑封面bitmap的尺寸是由注册remoteController时setArtworkConfiguration (int, int)来决定的

API文档

3.音乐控制

音乐的控制主要通过remoteController的sendMediaKeyEvent来实现需要注意的是音乐的控制在逻辑上是模拟按钮的点击动作来实现的，所以在send一个keyCode时需要先后send KEY_ACTION_DOWN和KEY_ACTION_UP两个event来实现，所以我的实现是这样的

  public boolean sendMusicKeyEvent(int keyCode) {
    if (!clientIdLost && remoteController != null) {
      // send "down" and "up" key events.
      KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, keyCode);
      boolean down = remoteController.sendMediaKeyEvent(keyEvent);
      keyEvent = new KeyEvent(KeyEvent.ACTION_UP, keyCode);
      boolean up = remoteController.sendMediaKeyEvent(keyEvent);
      return down && up;
    } else {
      long eventTime = SystemClock.uptimeMillis();
      KeyEvent key = new KeyEvent(eventTime, eventTime, KeyEvent.ACTION_DOWN, keyCode, 0);
      dispatchMediaKeyToAudioService(key);
      dispatchMediaKeyToAudioService(KeyEvent.changeAction(key, KeyEvent.ACTION_UP));
    }
    return false;
  }

  private void dispatchMediaKeyToAudioService(KeyEvent event) {
    AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
    if (audioManager != null) {
      try {
        audioManager.dispatchMediaKeyEvent(event);
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  }