public class MainActivity extends AppCompatActivity implements View.OnClickListener, SeekBar.OnSeekBarChangeListener, MediaPlayer.OnCompletionListener {private MediaPlayer mediaPlayer;//播放音频的private Button mPreviousBtn;private Button mPlayBtn;private Button mNextBtn;private ListView mListView;private List<Song> list;private MyAdapter adapter;private SeekBar mSeekBar;private TextView mCurrentTimeTv;private TextView mTotalTimeTv;// 记录当前播放歌曲的位置private int mCurrentPosition;private Handler mHandler=new Handler(new Handler.Callback() {@Overridepublic boolean handleMessage(Message message) {// 展示给进度条和当前时间int progress = mediaPlayer.getCurrentPosition();mSeekBar.setProgress(progress);mCurrentTimeTv.setText(parseTime(progress));// 继续定时发送数据
            updateProgress();return true;}});@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mediaPlayer = new MediaPlayer();mPreviousBtn= (Button) findViewById(R.id.mPreviousBtn);mPlayBtn= (Button) findViewById(R.id.mPlayBtn);mNextBtn= (Button) findViewById(R.id.mNextBtn);mCurrentTimeTv= (TextView) findViewById(R.id.current_time_tv);mTotalTimeTv= (TextView) findViewById(R.id.total_time_tv);mSeekBar= (SeekBar) findViewById(R.id.seek_bar);mSeekBar.setOnSeekBarChangeListener(this);mPreviousBtn.setOnClickListener(this);mPlayBtn.setOnClickListener(this);mNextBtn.setOnClickListener(this);initView();}/*** 初始化view*/private void initView() {mListView = (ListView) findViewById(R.id.main_listview);list = new ArrayList<>();//把扫描到的音乐赋值给listlist = MusicUtils.getMusicData(this);adapter = new MyAdapter(this,list);mListView.setAdapter(adapter);mediaPlayer.setOnCompletionListener(this);mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {//创建一个播放音频的方法，把点击到的地址传过去//list.get(i).path这个就是歌曲的地址
//                String path = list.get(i).path;
//                Log.i("WDD",path);
mCurrentPosition=i;changeMusic(mCurrentPosition);//                play(list.get(i).path);
//                String singer = list.get(i).singer;//歌手
//                String song = list.get(i).song;//歌曲名称
//                int duration = list.get(i).duration;//歌曲长度//                String time = MusicUtils.formatTime(duration);
//                String s=singer+"\n"+song+"\n"+time;
//                AlertDialog.Builder builder=new AlertDialog.Builder(MainActivity.this);
//                    builder.setTitle("歌曲");
//                    builder.setMessage(s);
//                    builder.show();
            }});}
//    /**
//     * 播放音频的方法
//     */
//    private void play(String path) {
//        //播放之前要先把音频文件重置
//        try {
//            mediaPlayer.reset();
//            //调用方法传进去要播放的音频路径
//            mediaPlayer.setDataSource(path);
//            //异步准备音频资源
//            mediaPlayer.prepareAsync();
//            //调用mediaPlayer的监听方法，音频准备完毕会响应此方法
//            mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
//                @Override
//                public void onPrepared(MediaPlayer mediaPlayer) {
//                    mediaPlayer.start();//开始音频
//                }
//            });
//        } catch (IOException e) {
//            e.printStackTrace();
//        }
//    }
@Overridepublic 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// 首次点击播放按钮，默认播放第0首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);}}// 基本数据类型和String在方法调用中传递的是值// 其他数据类型在方法调用中传递的是引用//切歌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 {// 切歌之前先重置，释放掉之前的资源
            mediaPlayer.reset();// 设置播放源
            mediaPlayer.setDataSource(list.get(position).path);// 开始播放前的准备工作，加载多媒体资源，获取相关信息
            mediaPlayer.prepare();// 开始播放
            mediaPlayer.start();} catch (IOException e) {e.printStackTrace();}// 切歌时重置进度条并展示歌曲时长mSeekBar.setProgress(0);mSeekBar.setMax(mediaPlayer.getDuration());mTotalTimeTv.setText(parseTime(mediaPlayer.getDuration()));updateProgress();}private void updateProgress() {// 使用Handler每间隔1s发送一次空消息，通知进度条更新Message msg = Message.obtain();// 获取一个现成的消息// 使用MediaPlayer获取当前播放时间除以总时间的进度int progress = mediaPlayer.getCurrentPosition();msg.arg1 = progress;mHandler.sendMessageDelayed(msg, INTERNAL_TIME);}private String parseTime(int oldTime) {SimpleDateFormat sdf = new SimpleDateFormat("mm:ss");// 时间格式String newTime = sdf.format(new Date(oldTime));return newTime;}private static final int INTERNAL_TIME = 1000;// 音乐进度间隔时间
    @Overridepublic void onProgressChanged(SeekBar seekBar, int i, boolean b) {}@Overridepublic void onStartTrackingTouch(SeekBar seekBar) {}// 当手停止拖拽进度条时执行该方法// 获取拖拽进度// 将进度对应设置给MediaPlayer
    @Overridepublic void onStopTrackingTouch(SeekBar seekBar) {int progress = seekBar.getProgress();mediaPlayer.seekTo(progress);}@Overridepublic void onCompletion(MediaPlayer mediaPlayer) {changeMusic(++mCurrentPosition);}
}

*** 音乐工具类,*/
public class MusicUtils {/*** 扫描系统里面的音频文件，返回一个list集合*/public static List<Song> getMusicData(Context context) {List<Song> list = new ArrayList<Song>();// 媒体库查询语句（写一个工具类MusicUtils）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) {// 注释部分是切割标题，分离出歌曲名和歌手 （本地媒体库读取的歌曲信息不规范）if (song.song.contains("-")) {String[] str = song.song.split("-");song.singer = str[0];song.song = str[1];}list.add(song);}}// 释放资源cursor.close();}return list;}/*** 定义一个方法用来格式化获取到的时间*/public static String formatTime(int time) {if (time / 1000 % 60 < 10) {return time / 1000 / 60 + ":0" + time / 1000 % 60;} else {return time / 1000 / 60 + ":" + time / 1000 % 60;}}
}

package com.example.lenovo.yinyuekao2;import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;import java.util.List;public class MyAdapter extends BaseAdapter {private Context context;private List<Song> list;public MyAdapter(MainActivity mainActivity, List<Song> list) {this.context = mainActivity;this.list = list;}@Overridepublic int getCount() {return list.size();}@Overridepublic Object getItem(int i) {return list.get(i);}@Overridepublic long getItemId(int i) {return i;}@Overridepublic View getView(final int i, View view, ViewGroup viewGroup) {ViewHolder holder = null;if (view == null) {holder = new ViewHolder();//引入布局view = View.inflate(context, R.layout.item_music_listview, null);//实例化对象holder.song = (TextView) view.findViewById(R.id.item_mymusic_song);holder.singer = (TextView) view.findViewById(R.id.item_mymusic_singer);holder.duration = (TextView) view.findViewById(R.id.item_mymusic_duration);holder.position = (TextView) view.findViewById(R.id.item_mymusic_postion);view.setTag(holder);} else {holder = (ViewHolder) view.getTag();}//给控件赋值holder.song.setText(list.get(i).song.toString());holder.singer.setText(list.get(i).singer.toString());//时间需要转换一下int duration = list.get(i).duration;String time = MusicUtils.formatTime(duration);holder.duration.setText(time);holder.position.setText(i+1+"");return view;}class ViewHolder{TextView song;//歌曲名TextView singer;//歌手TextView duration;//时长TextView position;//序号String parh;//地址}}

package com.example.lenovo.yinyuekao2;/*** Created by LENOVO on 2017/11/7.*//*** Created by user on 2016/6/24.* 放置音乐*/
public class Song {/*** 歌手*/public String singer;/*** 歌曲名*/public String song;/*** 歌曲的地址*/public String path;/*** 歌曲长度*/public int duration;/*** 歌曲的大小*/public long size;
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:id="@+id/activity_main"android:layout_width="match_parent"android:layout_height="match_parent"tools:context="com.example.lenovo.yinyuekao2.MainActivity"><LinearLayoutandroid:orientation="horizontal"android:id="@+id/main_textview"android:layout_width="match_parent"android:layout_height="40dp"><Buttonandroid:id="@+id/mPreviousBtn"android:text="上一曲"android:layout_width="0dp"android:layout_weight="1"android:layout_height="match_parent" /><Buttonandroid:id="@+id/mPlayBtn"android:text="播放/暂停"android:layout_width="0dp"android:layout_weight="1"android:layout_height="match_parent" /><Buttonandroid:id="@+id/mNextBtn"android:text="下一曲"android:layout_width="0dp"android:layout_weight="1"android:layout_height="match_parent" /></LinearLayout><RelativeLayoutandroid:id="@+id/main_textview1"android:layout_below="@+id/main_textview"android:layout_width="match_parent"android:layout_height="wrap_content"><TextViewandroid:id="@+id/current_time_tv"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="当前时间"/><TextViewandroid:id="@+id/total_time_tv"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignParentRight="true"android:text="全部时间"/><SeekBarandroid:id="@+id/seek_bar"style="?android:progressBarStyleHorizontal"android:layout_width="match_parent"android:layout_height="50dp"android:layout_toLeftOf="@id/total_time_tv"android:layout_toRightOf="@id/current_time_tv"/></RelativeLayout><ListViewandroid:id="@+id/main_listview"android:layout_below="@+id/main_textview1"android:layout_width="match_parent"android:layout_height="match_parent"/></RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="110dp"android:orientation="horizontal"android:gravity="center_vertical"android:padding="5dp"><TextViewandroid:id="@+id/item_mymusic_postion"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_margin="10dp"android:text="1"android:gravity="center"android:textColor="#0d0c0c"android:textSize="18sp" /><RelativeLayoutandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginLeft="20dp"><TextViewandroid:id="@+id/item_mymusic_song"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="歌曲名"android:textColor="#0d0c0c"android:textSize="20dp" /><TextViewandroid:id="@+id/item_mymusic_singer"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@+id/item_mymusic_song"android:text="歌手"android:textColor="#0d0c0c"android:textSize="15sp" /><TextViewandroid:id="@+id/item_mymusic_duration"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@+id/item_mymusic_song"android:layout_marginLeft="15dp"android:textColor="#0d0c0c"android:layout_toRightOf="@+id/item_mymusic_singer"android:text="时间"android:textSize="15sp" /></RelativeLayout></LinearLayout>