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我制作了一个流媒体播放器,它在单独的服务而不是 MainActivity 上运行。为了在用户寻找进度时更新 SeekBar 位置,我使用了一个广播接收器,它告诉服务用户寻找的位置。之后,该服务获取搜索位置并更新 MainActivity 中 SeekBar 的当前位置。

一切正常,但是当用户快速移动 SeekBar 时,服务类会冻结 MainActivity 的 UI,并且有时会崩溃。从 Service 类更新 MainActivity 的 SeekBar 的最佳方法是什么?

代码示例。,

主要活动,

 // Set up constant ID for broadcast of seekbar position
        public static final String BROADCAST_SEEKBAR = "com.gm.sendseekbar";
        private Intent intent;

         @Override
            public void onProgressChanged(SeekBar sb, int progress, boolean fromUser) {
                // TODO Auto-generated method stub
                if (fromUser) {
                    int seekPos = sb.getProgress();
                    intent.putExtra("seekpos", seekPos);
                    sendBroadcast(intent);
                }
            }

服务等级

@Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        mp = new MediaPlayer();
        mp.setOnBufferingUpdateListener(this);
        mp.setOnCompletionListener(this);
        mp.setOnInfoListener(this);
        mp.setOnPreparedListener(this);
        mp.setOnSeekCompleteListener(this);
        mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
        audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
        }

@Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        // Set up receiver for seekbar change
        registerReceiver(broadcastReceiver, new IntentFilter(
                ActivityMain.BROADCAST_SEEKBAR));

}

// Receive seekbar position if it has been changed by the user in the main activity
    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            sendBufferStartBroadcast();
            updateSeekPos(intent);
        }
    };

    // Update seek position from Activity
    public void updateSeekPos(Intent intent) {

        int seekPos = intent.getIntExtra("seekpos", 0);
        if (mp.isPlaying()) {

            int playPositionInMillisecconds = (mediaFileLengthInMilliseconds / 100)
                    * seekPos;
            mp.seekTo(playPositionInMillisecconds);

        }

    }
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1 回答 1

0

使用广播可能不是执行此操作的最佳方式,因为您不想告诉每个正在收听的应用程序您的应用程序的搜索栏已移动。为什么不使用 Service 和 Activity 通信?示例:http ://blog.philippheckel.com/2012/06/10/android-example-communication-between-activity-and-service-using-messaging/

于 2015-03-02T08:18:35.173 回答