android 播放音乐媒体文件（四）

mMediaPlayer 播放网络mp3
1.异步准备
使用

mMediaPlayer.prepareAsync();

2.监听prepareAsync结果
使用MediaPlayer.OnPreparedListener

3.获取长度
在public void onPrepared(MediaPlayer mp) 方法中可以获得长度

int duration = mMediaPlayer.getDuration();

4.获取缓存进度

使用：MediaPlayer.OnBufferingUpdateListener

大概代码像下面这样：

mMediaPlayer = new MediaPlayer();
mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
    @Override
    public void onPrepared(MediaPlayer mp) {
        btPlayStop.setEnabled(true);
        int duration = mMediaPlayer.getDuration();
        sbMusicProcess.setMax(duration);
        mHandler.sendEmptyMessage(1);
        mMediaPlayer.start();
        btPlayStop.setChecked(PLAYING);
    }
});
try {
    mMediaPlayer.setDataSource(mp3url);
} catch (IOException e) {
    e.printStackTrace();
}
mMediaPlayer.prepareAsync();

mMediaPlayer.setOnBufferingUpdateListener(new MediaPlayer.OnBufferingUpdateListener() {
    @Override
    public void onBufferingUpdate(MediaPlayer mp, int percent) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                sbMusicProcess.setSecondaryProgress((sbMusicProcess.getMax() * process / 100));
            }
        });
    }
});

mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
    @Override
    public void onCompletion(MediaPlayer mp) {
        mp.reset();
        btPlayStop.setChecked(READY);
    }
});

prepare 与prepareAsync()的区别

后台推荐网络和异步使用。

prepareAsync()工作原理分析

参考：

http://blog.csdn.net/hejjunlin/article/details/52420803

至此MediaPlayer已可以满足基本的音乐播放需求。