【Android】_音乐列表_仿网易云音乐播放器2(读取本地mp3)

上期博客链接：https://blog.csdn.net/cungudafa/article/details/85318725
本次项目是在上次项目上的一个扩展，上次简单实现了音乐播放与动画旋转;
这次我们要实现读取本地mp3格式所以音乐，以列表形式存放，点击跳转&播放。

一、读取本地文件

权限：

  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

二、MusicDemo实现

我们大致想要的效果（目前未美化）：

分析：
1、封装类： 为了更好的管理我们的文件，我们需要单独建立一个类来管理MP3文件的属性值，新建类命名为MusicInfo.java
2、读取： 再新建一个类查询数据库取得MP3文件，并分离取得各属性值，MusicUtil.java
3、美化： 新建list.xml用适配器MusicListAdapter.java将读取内容存放于列表形式显示
4、显示：

• 总项目结构：
  

三、具体实现类

1、MusicInfo：

package com.example.cungu.musicdemo;

//为了更好的管理我们的文件，我们需要单独建立一个类来管理MP3文件的属性值，新建类命名为MusicInfo.java:
public class MusicInfo {
    private long id; // 歌曲ID
    private String title; // 歌曲名称
    private String album; // 专辑
    private long albumId;//专辑ID
    private String displayName; //显示名称
    private String artist; // 歌手名称
    private long duration; // 歌曲时长
    private long size; // 歌曲大小
    private String url; // 歌曲路径
    private String lrcTitle; // 歌词名称
    private String lrcSize; // 歌词大小

    public MusicInfo() {
        super();
    }

    public MusicInfo(long id, String title, String album, long albumId,
                     String displayName, String artist, long duration, long size,
                     String url, String lrcTitle, String lrcSize) {
        super();
        this.id = id;
        this.title = title;
        this.album = album;
        this.albumId = albumId;
        this.displayName = displayName;
        this.artist = artist;
        this.duration = duration;
        this.size = size;
        this.url = url;
        this.lrcTitle = lrcTitle;
        this.lrcSize = lrcSize;
    }
    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAlbum() {
        return album;
    }

    public void setAlbum(String album) {
        this.album = album;
    }

    public long getAlbumId() {
        return albumId;
    }

    public void setAlbumId(long albumId) {
        this.albumId = albumId;
    }

    public String getArtist() {
        return artist;
    }

    public void setArtist(String artist) {
        this.artist = artist;
    }

    public long getDuration() {
        return duration;
    }

    public void setDuration(long duration) {
        this.duration = duration;
    }

    public long getSize() {
        return size;
    }

    public void setSize(long size) {
        this.size = size;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getLrcTitle() {
        return lrcTitle;
    }

    public void setLrcTitle(String lrcTitle) {
        this.lrcTitle = lrcTitle;
    }

    public String getLrcSize() {
        return lrcSize;
    }

    public void setLrcSize(String lrcSize) {
        this.lrcSize = lrcSize;
    }

    public String getDisplayName() {
        return displayName;
    }

    public void setDisplayName(String displayName) {
        this.displayName = displayName;
    }
}

2、MusicUtil

package com.example.cungu.musicdemo;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.provider.MediaStore;
//再新建一个类查询数据库取得MP3文件，并分离取得各属性值，MusicUtil.java：
public class MusicUtil {

    public static List<MusicInfo> getMp3Infos(Context context) {
        Cursor cursor = context.getContentResolver().query(
                MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null,
                MediaStore.Audio.Media.DEFAULT_SORT_ORDER);

        List<MusicInfo> musicInfos = new ArrayList<MusicInfo>();
        for (int i = 0; i < cursor.getCount(); i++) {
            cursor.moveToNext();
            MusicInfo musicInfo = new MusicInfo();
            long id = cursor.getLong(cursor
                    .getColumnIndex(MediaStore.Audio.Media._ID));	//音乐id
            String title = cursor.getString((cursor
                    .getColumnIndex(MediaStore.Audio.Media.TITLE))); // 音乐标题
            String artist = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.ARTIST)); // 艺术家
            String album = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.ALBUM));	//专辑
            String displayName = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
            long albumId = cursor.getInt(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
            long duration = cursor.getLong(cursor
                    .getColumnIndex(MediaStore.Audio.Media.DURATION)); // 时长
            long size = cursor.getLong(cursor
                    .getColumnIndex(MediaStore.Audio.Media.SIZE)); // 文件大小
            String url = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.DATA)); // 文件路径
            int isMusic = cursor.getInt(cursor
                    .getColumnIndex(MediaStore.Audio.Media.IS_MUSIC)); // 是否为音乐
            if (isMusic != 0) { // 只把音乐添加到集合当中
                musicInfo.setId(id);
                musicInfo.setTitle(title);
                musicInfo.setArtist(artist);
                musicInfo.setAlbum(album);
                musicInfo.setDisplayName(displayName);
                musicInfo.setAlbumId(albumId);
                musicInfo.setDuration(duration);
                musicInfo.setSize(size);
                musicInfo.setUrl(url);
                musicInfos.add(musicInfo);
            }
        }
        return musicInfos;
    }

    public static List<HashMap<String, String>> getMusicMaps(
            List<MusicInfo> mp3Infos) {
        List<HashMap<String, String>> mp3list = new ArrayList<HashMap<String, String>>();
        for (Iterator iterator = mp3Infos.iterator(); iterator.hasNext();) {
            MusicInfo musicInfo = (MusicInfo) iterator.next();
            HashMap<String, String> map = new HashMap<String, String>();
            map.put("title", musicInfo.getTitle());
            map.put("Artist", musicInfo.getArtist());
            map.put("album", musicInfo.getAlbum());
            map.put("displayName", musicInfo.getDisplayName());
            map.put("albumId", String.valueOf(musicInfo.getAlbumId()));
            map.put("duration", formatTime(musicInfo.getDuration()));
            map.put("size", String.valueOf(musicInfo.getSize()));
            map.put("url", musicInfo.getUrl());
            mp3list.add(map);
        }
        return mp3list;
    }

    /**
     * 格式化时间，将毫秒转换为分:秒格式
     * @param time
     * @return
     */
    public static String formatTime(long time) {
        // TODO Auto-generated method stub
        String min = time / (1000 * 60) + "";
        String sec = time % (1000 * 60) + "";
        if (min.length() < 2) {
            min = "0" + time / (1000 * 60) + "";
        } else {
            min = time / (1000 * 60) + "";
        }
        if (sec.length() == 4) {
            sec = "0" + (time % (1000 * 60)) + "";
        } else if (sec.length() == 3) {
            sec = "00" + (time % (1000 * 60)) + "";
        } else if (sec.length() == 2) {
            sec = "000" + (time % (1000 * 60)) + "";
        } else if (sec.length() == 1) {
            sec = "0000" + (time % (1000 * 60)) + "";
        }
        return min + ":" + sec.trim().substring(0, 2);
    }
}

3、MusicListAdapter：

package com.example.cungu.musicdemo;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MusicListAdapter extends BaseAdapter{

    private Context context;
    private List<MusicInfo> musicInfos;
    private MusicInfo musicInfo;
    /**
     * 构造函数
     * @param context	上下文
     * @param mp3Infos  集合对象
     */
    public MusicListAdapter(Context context, List<MusicInfo> mp3Infos) {
        this.context = context;
        this.musicInfos = mp3Infos;
    }
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return musicInfos.size();
    }
    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder = null;
        if(convertView == null)
        {
            viewHolder = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(R.layout.list, null);
            viewHolder.musicTitle = (TextView) convertView.findViewById(R.id.name);
            viewHolder.musicDuration = (TextView) convertView.findViewById(R.id.time);
            viewHolder.musicArtist = (TextView) convertView.findViewById(R.id.actor);
            convertView.setTag(viewHolder);			//表示给View添加一个格外的数据，
        } else {
            viewHolder = (ViewHolder)convertView.getTag();//通过getTag的方法将数据取出来
        }
        musicInfo = musicInfos.get(position);
        viewHolder.musicTitle.setText(musicInfo.getTitle());		//显示标题
        viewHolder.musicArtist.setText(musicInfo.getArtist());		//显示艺术家
        viewHolder.musicDuration.setText(MusicUtil.formatTime(musicInfo.getDuration()));//显示时长

        return convertView;
    }

    /**
     * 定义一个内部类
     * 声明相应的控件引用
     *
     */
    public class ViewHolder {
        //所有控件对象引用
        public ImageView albumImage;	//专辑图片
        public TextView musicTitle;		//音乐标题
        public TextView musicDuration;	//音乐时长
        public TextView musicArtist;	//音乐艺术家
    }

}

4、list.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/actor"
        android:layout_alignBottom="@+id/actor"
        android:layout_alignParentRight="true"
        android:layout_marginRight="28dp"
        android:text="time"
        android:textColor="#ffffff"/>

    <TextView
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="2dp"
        android:layout_marginLeft="24dp"
        android:text="name"
        android:textColor="#ffffff"
        android:textSize="18sp" />

    <TextView
        android:id="@+id/actor"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/name"
        android:layout_below="@+id/name"
        android:textColor="#ffffff"
        android:text="actor"
        android:textSize="12sp"/>
RelativeLayout>

5、activity_player_list.xml主界面：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/music_play_background">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_marginTop="25dp"
        android:orientation="horizontal">
        <ImageButton
            android:id="@+id/btn_MusicList2"
            android:layout_width="35dp"
            android:layout_height="35dp"
            android:layout_gravity="center_vertical"
            android:background="?attr/actionModeCloseDrawable"
            android:backgroundTint="#ccffffff" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="20dp"
            android:text="音乐列表"
            android:layout_gravity="center_vertical"
            android:textColor="#ffffff"
            android:textSize="20sp" />

    LinearLayout>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="0.5dp"
        android:background="#afafaf"
        android:layout_below="@+id/title"/>
    <ListView
        android:id="@+id/list"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >
    ListView>
LinearLayout>

PlayerListActivity.java:

package com.example.cungu.musicdemo;

import android.app.Activity;

import java.io.Serializable;
import java.util.List;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

public class PlayerListActivity extends Activity implements AdapterView.OnItemLongClickListener {
    private ListView listview;
    private List<MusicInfo> musicInfos = null;
    private MusicListAdapter Listadapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_player_list);
        listview = (ListView) findViewById(R.id.list);

        musicInfos = MusicUtil.getMp3Infos(PlayerListActivity.this);
        Listadapter = new MusicListAdapter(this, musicInfos);
        listview.setAdapter(Listadapter);
        listview.setOnItemLongClickListener(this);
    }

    @Override
    public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
        Intent intent=new Intent();
        intent.putExtra("music", (Serializable) musicInfos);
        intent.setClass(this, MainActivity.class);
        startActivity(intent);
        return false;
    }
}

---

待解决问题：
如何把用适配器里的内容传给播放界面，播放！