android videoView 加载等待

final Handler handler = new Handler();
Runnable runnable = new Runnable() {
    public void run() {
        int duration = mVideoView.getCurrentPosition();
        if(mVideoView.isPlaying()){
            if (old_duration == duration) {
                mProgressBar.setVisibility(View.VISIBLE);
            } else {
                mProgressBar.setVisibility(View.GONE);
            }
        }
        old_duration = duration;
        handler.postDelayed(runnable, 500);
    }
};

handler.postDelayed(runnable, 0);