快进后退无效，拖动seekbar松开后又返回到当时播放位置。
希望得到技术支持一下。谢谢！

private SeekBar.OnSeekBarChangeListener mSeekListener = new SeekBar.OnSeekBarChangeListener() {

    public void onStartTrackingTouch(SeekBar bar) {
        mDragging = true;
        show(3600000);
        mHandler.removeMessages(SHOW_PROGRESS);
        if (mInstantSeeking)
            mAM.setStreamMute(AudioManager.STREAM_MUSIC, true);
    }

    public void onProgressChanged(SeekBar bar, int progress, boolean fromuser) {
        if (!fromuser) {
            return;
        }
        final long newposition = (long) (mDuration * progress) / 1000;
        String time = generateTime(newposition);
        if (mInstantSeeking) {
            mHandler.removeCallbacks(mLastSeekBarRunnable);
            mLastSeekBarRunnable = new Runnable() {
                @Override
                public void run() {
                    mPlayer.seekTo(newposition);
                }
            };
            mHandler.postDelayed(mLastSeekBarRunnable, SEEK_TO_POST_DELAY_MILLIS);
        }
        if (mCurrentTime != null)
            mCurrentTime.setText(time);
    }

    public void onStopTrackingTouch(SeekBar bar) {
        if (mInstantSeeking)
            mPlayer.seekTo(mDuration * bar.getProgress() / 1000);

        show(sDefaultTimeout);
        mHandler.removeMessages(SHOW_PROGRESS);
        mAM.setStreamMute(AudioManager.STREAM_MUSIC, false);
        mDragging = false;
        mHandler.sendEmptyMessageDelayed(SHOW_PROGRESS, 1000);
    }
};