单击通知中的按钮时如何更新活动 UI？

Question

我制作了一个媒体播放器应用程序，它通过服务在后台播放歌曲。 我有一个通知，显示上一个、暂停/播放和下一个按钮。

这些按钮可以工作，但是当我单击通知中的暂停/播放按钮时，我想更改活动中的暂停/播放按钮状态。

因此，例如，当我在通知中暂停歌曲时，我希望它也更改我的活动中的按钮暂停可绘制。

我怎样才能做到这一点？

我的服务中的通知代码通过传递 playBackStatus（上一个、暂停/播放、下一个）来处理按钮状态。

private void NotificationBuilder(PlaybackStatus playbackStatus){
    int notificationAction = R.drawable.ic_action_pause_white;
    PendingIntent play_pause_action = null;

    if (playbackStatus == PlaybackStatus.PLAYING){
        //Pause button created when song is PLAYING
        notificationAction = R.drawable.ic_action_pause_white;
        play_pause_action = playbackAction(1);


    }else if (playbackStatus == PlaybackStatus.PAUSED){
        //Play button created when song is PAUSED
        notificationAction = R.drawable.ic_action_play;
        play_pause_action = playbackAction(0);

    }

编辑：

play_pause_action 是 PendingIntent

notificationBuilder.setShowWhen(false)
            .setStyle(new android.support.v4.media.app.NotificationCompat.MediaStyle().setMediaSession(mMediaSessionCompat.getSessionToken()).setShowActionsInCompactView(0, 1 ,2))
            .setSmallIcon(android.R.drawable.stat_sys_headset).setContentTitle(activeSong.getTitle()).setContentText(activeSong.getArtist())
            .addAction(R.drawable.ic_action_prev_white, null, playbackAction(3))
            .addAction(notificationAction, null, play_pause_action).addAction(R.drawable.ic_action_next_white, null, playbackAction(2))
            .setColor(getResources().getColor(R.color.theme1));

 private PendingIntent playbackAction(int actionNumber) {
        Intent playbackAction = new Intent(this, MediaPlayerService.class);
        switch (actionNumber) {
            case 0:
                // Play
                playbackAction.setAction(Constants.ACTIONS.mACTION_PLAY);
                return PendingIntent.getService(this, actionNumber, playbackAction, 0);
            case 1:
                // Pause
                playbackAction.setAction(Constants.ACTIONS.mACTION_PAUSE);
                return PendingIntent.getService(this, actionNumber, playbackAction, 0);
            case 2:
                // Next track
                playbackAction.setAction(Constants.ACTIONS.mACTION_NEXT);
                return PendingIntent.getService(this, actionNumber, playbackAction, 0);
            case 3:
                // Previous track
                playbackAction.setAction(Constants.ACTIONS.mACTION_PREVIOUS);
                return PendingIntent.getService(this, actionNumber, playbackAction, 0);
            default:
                break;
        }
        return null;
    }

Answer 1

尝试这个 ：

Button btn=((Button)MainActivity.this.findViewById(R.id.btnPlay));


if (playbackStatus == PlaybackStatus.PLAYING){
        //Pause button created when song is PLAYING
        btn.setImageResource(R.drawable.pause); 
        notificationAction = R.drawable.ic_action_pause_white;
        play_pause_action = playbackAction(1);


}else if (playbackStatus == PlaybackStatus.PAUSED){
      //Play button created when song is PAUSED
       btn.setImageResource(R.drawable.play);
       notificationAction = R.drawable.ic_action_play;
       play_pause_action = playbackAction(0);

}

Answer 2

创建一个界面，然后您就可以处理按钮。在您的界面中添加一个方法，例如示例 handleMybutton (View v){ handle your button what ever you want to do }