Android第三次作业

1、实现的功能

(1)实现播放，暂停，播放上一首，下一首功能

(2)显示播放列表

(3)可以播放3首歌曲

2、项目截图

想要歌曲在列表上显示出来，首先我们要将音乐导入到模拟器的sd目录下，刚开始导的时候没有导进去，原因是没有将其名字改为英文，我将音乐名字改为英文时就可以运行。

3、主要功能代码

（1）按钮实现功能

public void onClick(View view) {
    if (view.getId()==R.id.mPreviousBtn){//上一曲
        changeMusic(--mCurrentPosition);
    }else if (view.getId()==R.id.mPlayBtn){//暂停/播放
        if (mediaPlayer==null){
            changeMusic(0);
        }else {
            if (mediaPlayer.isPlaying()){
                mediaPlayer.pause();
            }else {
                mediaPlayer.start();
            }
        }
    }else if (view.getId()==R.id.mNextBtn){// 下一首
        changeMusic(++mCurrentPosition);
    }
}
（2）实现切歌功能

private void changeMusic(int position){
    if (position<0){
        mCurrentPosition = position =list.size()-1;
    }else if (position>list.size()-1){
        mCurrentPosition = position=0;
    }

    if (mediaPlayer==null){
        mediaPlayer=new MediaPlayer();
    }

    try {
        mediaPlayer.reset();
        mediaPlayer.setDataSource(list.get(position).path);
        mediaPlayer.prepare();
        mediaPlayer.start();
    } catch (IOException e) {
        e.printStackTrace();
    }

    mSeekBar.setProgress(0);
    mSeekBar.setMax(mediaPlayer.getDuration());
    mTotalTimeTv.setText(parseTime(mediaPlayer.getDuration()));

    updateProgress();
}
（3）获取音乐数据

Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null,
        null, MediaStore.Audio.AudioColumns.IS_MUSIC);
if (cursor != null) {
    while (cursor.moveToNext()) {
        Song song = new Song();
        song.song = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME));
        song.singer = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
        song.path = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));
        song.duration = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));
        song.size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE));
        if (song.size > 1000 * 800) {

            if (song.song.contains("-")) {
                String[] str = song.song.split("-");
                song.singer = str[0];
                song.song = str[1];
            }
4、app项目截图

5、项目git地址及apk项目地址
（1）项目git地址
https://git.coding.net/mj1600802019/MedioPlayer.git
（2）apk项目地址
https://git.coding.net/mj1600802019/MedioPlayer.git

(3)录屏地址
http://screen-recording.oss-cn-beijing.aliyuncs.com/QQ%E8%A7%86%E9%A2%91_68F08B37CDCAD4A60F87B6381326208C-ffa095aab022d24aeabe768b4ba710d4?Expires=1546685112&OSSAccessKeyId=LTAIjO6kd43sVLBM&Signature=gnhXEWCZ3yR9bSHSFLn7FYkvypQ%3D