Android 基础——本地音乐播放器

//MainActivity中代码如下：

import android.content.ContentResolver;
import android.database.Cursor;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private TextView singerName,singer;
    private ArrayList<MusicInfo> list=new ArrayList<>();
    private MediaPlayer play;
    private int number;
    MyAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //初始化控件
        listView = (ListView)findViewById(R.id.listView);
        singerName = (TextView)findViewById(R.id.singName);
        singer = (TextView)findViewById(R.id.singer);
        //设置数据源

        //给ListView添加适配器
        adapter = new MyAdapter(list, this);
        listView.setAdapter(adapter);
        //加载本地音乐
        loadLocalData();
        //初始化媒体播放器
        play = new MediaPlayer();
        //设置点击事件
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                number=position;
                MusicInfo info = list.get(position);
                singer.setText(info.getSinger());
                singerName.setText(info.getSingName());
                //因为有可能其他音乐正在被播放，所以要先停止再播放
                stopMusic();
                //播放音乐
                play.reset();
                try {
                    play.setDataSource(info.getPath());
                    playMusic();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });

    }
    private void loadLocalData() {
        //1.获得ContentResolver对象
        ContentResolver resolver = getContentResolver();
        //2.获得Uri地址
        Uri musicuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        //3.查找地址中的内容
        Cursor cursor = resolver.query(musicuri, null, null, null, null);
        //4.遍历cursor信息
        int id=0;
        while (cursor.moveToNext()){
            String title = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE));
            String displayname = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
            String singer = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
            String path = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
            String album = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM));

            long duration = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION));
            SimpleDateFormat sdf = new SimpleDateFormat("mm:ss");
            String time = sdf.format(new Date(duration));
            id++;
            String idStr = id+"";
            MusicInfo info = new MusicInfo(idStr,title,singer,album,time,path);
            list.add(info);

        }
        adapter.notifyDataSetChanged();
    }
    /**播放音乐*/
    private void playMusic() {
        if (play!=null&&!play.isPlaying()){
            try {
                play.prepare();//准备播放
                play.start();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }
    /**停止音乐*/
    private void stopMusic() {
        if (play!=null&&play.isPlaying()){
            play.pause();
            play.seekTo(0);
            play.stop();
        }
    }
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.next_btn://下一个，需要显示下一首歌曲
                //获取数据
				number++;
                MusicInfo info = list.get(number);
                singer.setText(info.getSinger());
                singerName.setText(info.getSingName());
                //因为有可能其他音乐正在被播放，所以要先停止再播放
                stopMusic();
                //播放音乐
                play.reset();
                try {
                    play.setDataSource(info.getPath());
                    playMusic();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                break;
            case R.id.stop_btn://暂停
                if (play!=null){
                    if (play.isPlaying()){//暂停
                        play.pause();
                    }else if (!play.isPlaying()){//开始
                        play.start();
                    }
                }
                break;

        }
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        stopMusic();
    }

}

//内容实体类：

public class MusicInfo {
    private String id;
    private String singName;
    private String singer;
    private String alumb;
    private String time;
    private String path;
    public MusicInfo() {
    }
    public MusicInfo(String id, String singName, String singer, String alumb, String time, String path) {
        this.id = id;
        this.singName = singName;
        this.singer = singer;
        this.alumb = alumb;
        this.time = time;
        this.path = path;
    }

    public String getId() {
        return id;
    }

    public String getSingName() {
        return singName;
    }

    public String getSinger() {
        return singer;
    }

    public String getAlumb() {
        return alumb;
    }

    public String getTime() {
        return time;
    }

    public String getPath() {
        return path;
    }

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

    public void setSingName(String singName) {
        this.singName = singName;
    }

    public void setAlumb(String alumb) {
        this.alumb = alumb;
    }

    public void setSinger(String singer) {
        this.singer = singer;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public void setTime(String time) {
        this.time = time;
    }

    @Override
    public String toString() {
        return "MusicInfo{" +
                "id='" + id + '\'' +
                ", singName='" + singName + '\'' +
                ", singer='" + singer + '\'' +
                ", alumb='" + alumb + '\'' +
                ", time='" + time + '\'' +
                ", path='" + path + '\'' +
                '}';
    }
}

//listView需要一个适配器器

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

import java.util.ArrayList;

/**
 * Created by Administrator on 2018/1/4 0004.
 */

public class MyAdapter extends BaseAdapter{
    private ArrayList<MusicInfo> list;
    private Context context;

    public MyAdapter(ArrayList<MusicInfo> list, Context context) {
        this.list = list;
        this.context = context;
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView==null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.item_layout,null);
            holder = new ViewHolder(convertView);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }
        MusicInfo musicInfo = list.get(position);
        holder.idTv.setText(musicInfo.getId());
        holder.titleTv.setText(musicInfo.getSingName());
        holder.alubmTv.setText(musicInfo.getAlumb());
        holder.singerTv.setText(musicInfo.getSinger());
        holder.timeTv.setText(musicInfo.getTime());
        return convertView;
    }
    class ViewHolder{
        TextView idTv,titleTv,singerTv,alubmTv,timeTv;
        public ViewHolder(View itemView){
            idTv = (TextView) itemView.findViewById(R.id.item_music_id);
            titleTv = (TextView) itemView.findViewById(R.id.item_music_sing);
            singerTv = (TextView) itemView.findViewById(R.id.item_music_singer);
            alubmTv = (TextView) itemView.findViewById(R.id.item_music_album);
            timeTv = (TextView) itemView.findViewById(R.id.item_music_time);
        }
    }
}

//主界面布局

<?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.operation_20180104_music.MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:background="#FFF"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true">
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/music_icon"
            android:id="@+id/image"
            android:layout_centerVertical="true"/>
        <TextView
            android:id="@+id/singName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:text="歌名"
            android:textSize="22sp"
            android:layout_toRightOf="@+id/image"
            android:padding="10dp"
            android:layout_marginTop="5dp"/>

        <TextView
            android:id="@+id/singer"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="张朝韩"
            android:textSize="16sp"
            android:padding="10dp"
            android:layout_alignBottom="@+id/image"
            android:layout_toRightOf="@+id/image"
            android:layout_toEndOf="@+id/image" />
        <ImageButton
            android:id="@+id/next_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/image01"
            android:layout_alignParentRight="true"
            android:background="#FFF"
            android:onClick="onClick"/>

        <ImageButton
            android:id="@+id/stop_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/image02"
            android:background="#FFF"
            android:layout_toLeftOf="@+id/next_btn"
            android:onClick="onClick"/>

    </RelativeLayout>
</RelativeLayout>

//listView中内容的布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <TextView
        android:id="@+id/item_music_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="1"
        android:textSize="24sp"
        android:textStyle="bold"
        android:layout_centerVertical="true"/>
    <TextView
        android:id="@+id/item_music_sing"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="玫瑰花的葬礼"
        android:textSize="20sp"
        android:textStyle="bold"
        android:singleLine="true"
        android:ellipsize="end"
        android:layout_marginLeft="20dp"
        android:layout_toRightOf="@+id/item_music_id"/>
    <TextView
        android:id="@+id/item_music_singer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="许嵩"
        android:textSize="16sp"
        android:textColor="#888"
        android:layout_marginTop="10dp"
        android:layout_alignLeft="@+id/item_music_sing"
        android:layout_below="@+id/item_music_sing"/>
    <TextView
        android:id="@+id/line"
        android:layout_width="2dp"
        android:layout_height="20dp"
        android:background="#ccc"
        android:layout_toRightOf="@+id/item_music_singer"
        android:layout_alignTop="@+id/item_music_singer"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"/>
    <TextView
        android:id="@+id/item_music_album"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="专辑名称"
        android:layout_marginTop="10dp"
        android:textSize="16sp"
        android:textColor="#888"
        android:ellipsize="end"
        android:singleLine="true"
        android:layout_toRightOf="@+id/line"
        android:layout_below="@+id/item_music_sing"/>
    <TextView
        android:id="@+id/item_music_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp"
        android:layout_below="@+id/item_music_singer"
        android:text="4:30"
        android:layout_alignParentRight="true"/>
</RelativeLayout>

//一个简单的本地音乐播放器完成

原文链接：https://blog.csdn.net/qq_40913813/article/details/78986838