java - Android:从应用程序外部控制 MediaPlayer 实例(对象)？

Question

我开发了一个新闻 Android 应用程序，该应用程序使用 MediaPlayer 类从 SoundCloud 流式传输新闻广播轨道，一切正常。现在假设用户从应用程序内部按下播放按钮，音乐开始播放。现在，用户按下硬件主页按钮，应用程序进入后台，或者用户按下 sleep 按钮关闭屏幕。我已经设法让音乐在后台播放，但我希望用户能够从应用程序外部控制 MediaPlayer(暂停、停止、下一个、上一个操作)。

我搜索了很多，但没有找到任何东西，我该怎么做？

我没有放置我的代码，因为我认为它不相关，如果您想查看代码，请告诉我。

提前致谢。

Answer 1

我通过添加带有图像/按钮的自定义通知来控制 Android 通知栏的音频播放和 channel ，从而完成了类似的操作。

我认为这就是你所追求的。

通知代码:

public Notification buildNotification()
   {
      Intent intent = new Intent(mContext, MainActivity.class);
      PendingIntent pIntent = PendingIntent.getActivity(mContext, 0, intent, 0);

      setContentView();

      Notification.Builder notibuilder = new Notification.Builder(mContext);
         notibuilder.setContentTitle(" ");
         notibuilder.setContentText(" ");
         notibuilder.setSmallIcon(R.drawable.ic_launcher);
         notibuilder.setOngoing(true);
         notibuilder.setAutoCancel(false);
         notibuilder.setContentIntent(pIntent);
         notibuilder.setContent(mContentView);
         notibuilder.setTicker(null);


         mNotification = notibuilder.build();

      NotificationManager notificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);

      return mNotification;
   }

   public void setContentView()
   {
      mContentView = new RemoteViews(mContext.getPackageName(), R.layout.custom_notification);
      mContentView.setTextViewText(R.id.notificaiton_app_title, "");

      String currentChannel = "  ";
      if ( mCurrentChannel != -1)
         currentChannel = " " + (mCurrentChannel + 1);
      mContentView.setTextViewText(R.id.notificaiton_app_channel, currentChannel);

      Intent previousIntent = new Intent(mContext, NotificationButtonIntentService.class);
      previousIntent.setAction(NotificationButtonIntentService.Action_Previous);
      mContentView.setOnClickPendingIntent(R.id.notification_layout_previous, PendingIntent.getService(mContext, 0, previousIntent,  PendingIntent.FLAG_CANCEL_CURRENT));
      mContentView.setOnClickPendingIntent(R.id.notification_image_previous, PendingIntent.getService(mContext, 0, previousIntent,  PendingIntent.FLAG_CANCEL_CURRENT));

      Intent playIntent = new Intent(mContext, NotificationButtonIntentService.class);

      if ( mCurrentChannel != -1)
      {
         playIntent.setAction(NotificationButtonIntentService.Action_Pause);
         mContentView.setInt(R.id.notification_image_play_pause, "setBackgroundResource", R.drawable.ic_media_pause);
      }
      else
      {
         playIntent.setAction(NotificationButtonIntentService.Action_Play);
         mContentView.setInt(R.id.notification_image_play_pause, "setBackgroundResource", R.drawable.ic_media_play);
      }

      mContentView.setOnClickPendingIntent(R.id.notification_layout_play_pause, PendingIntent.getService(mContext, 0, playIntent, PendingIntent.FLAG_CANCEL_CURRENT));
      mContentView.setOnClickPendingIntent(R.id.notification_image_play_pause, PendingIntent.getService(mContext, 0, playIntent, PendingIntent.FLAG_CANCEL_CURRENT));

      Intent nextIntent = new Intent(mContext, NotificationButtonIntentService.class);
      nextIntent.setAction(NotificationButtonIntentService.Action_Next);
      mContentView.setOnClickPendingIntent(R.id.notification_layout_next, PendingIntent.getService(mContext, 0, nextIntent, PendingIntent.FLAG_CANCEL_CURRENT));
      mContentView.setOnClickPendingIntent(R.id.notification_image_next, PendingIntent.getService(mContext, 0, nextIntent, PendingIntent.FLAG_CANCEL_CURRENT));

      Intent closeIntent = new Intent(mContext, NotificationButtonIntentService.class);
      closeIntent.setAction(NotificationButtonIntentService.Action_Close);
      mContentView.setOnClickPendingIntent(R.id.notification_layout_close, PendingIntent.getService(mContext, 0, closeIntent, PendingIntent.FLAG_CANCEL_CURRENT));
      mContentView.setOnClickPendingIntent(R.id.notification_image_close, PendingIntent.getService(mContext, 0, closeIntent, PendingIntent.FLAG_CANCEL_CURRENT));
   }

布局:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout 
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:layout_centerVertical="true"
    android:layout_alignParentLeft="true" >

    <ImageView
        android:id="@+id/notification_app_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:paddingLeft="12dp"
        android:src="@drawable/ic_stat_zipstreamer" />

    <TextView
        android:id="@+id/notificaiton_app_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >

        <TextView
            android:id="@+id/notificaiton_app_channel"
            style="@style/notification.channel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:ems="2" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/notification_layout_previous"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >

        <ImageButton
            android:id="@+id/notification_image_previous"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:background="@drawable/ic_media_previous" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/notification_layout_play_pause"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >

        <ImageButton
            android:id="@+id/notification_image_play_pause"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:background="@drawable/ic_media_play" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/notification_layout_next"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >

        <ImageButton
            android:id="@+id/notification_image_next"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:background="@drawable/ic_media_next" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/notification_layout_close"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_weight="1" >

        <ImageButton
            android:id="@+id/notification_image_close"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:background="@drawable/ic_media_close" />
    </RelativeLayout>

</LinearLayout>
</RelativeLayout>

意向服务:

public class NotificationButtonIntentService extends IntentService
{

   public static final String TAG = "NotificationButtonIntentService";

   public static final String Action_Play = "play";
   public static final String Action_Pause = "pause";
   public static final String Action_Previous = "previous";
   public static final String Action_Next = "next";
   public static final String Action_Close = "close";

   public NotificationButtonIntentService() 
   {
      super("");
   }

   public NotificationButtonIntentService(String name)
   {
      super(name);

   }

   @Override
   protected void onHandleIntent(Intent intent)
   {
      String action = intent.getAction();
      String realAction = intent.getAction();

      if (realAction != null) 
      {
          if (realAction.equals(Action_Play)) 
          {
             EventBus.getDefault().post(new PlayControlEvent(PlayControlEvent.PlayAction.PLAY));    
          } 
          else if (realAction.equals(Action_Pause)) 
          {
             EventBus.getDefault().post(new PlayControlEvent(PlayControlEvent.PlayAction.PAUSE));    
          } 
          else if (realAction.equals(Action_Close)) 
          {
              EventBus.getDefault().post(new ShutdownEvent());
          }
          else if ( realAction.equals(Action_Next))
          {
             EventBus.getDefault().post(new PlayControlEvent(PlayControlEvent.PlayAction.NEXT_CHANNEL));
          }
          else if ( realAction.equals(Action_Previous))
          {
             EventBus.getDefault().post(new PlayControlEvent(PlayControlEvent.PlayAction.PREVIOUS_CHANNEL));
          }
      }
   }
}