Android 音乐播放器（暂停、下一首、上一首）

1.编写主页面，使用listview组件放置音乐列表信息

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical"
    android:background="#D8D8D8">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/local" >
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">


    <com.example.myapplication.MyListVIew
        android:id="@+id/video_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
       />
        </LinearLayout>
    </ScrollView>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="70dp"
        android:id="@+id/local"
        android:background="#ECC8C8"
        android:layout_alignParentBottom="true">

        <ImageView
            android:id="@+id/img"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:src="@drawable/bold"
            android:layout_marginLeft="10dp"
            android:layout_centerVertical="true"/>

        <TextView
            android:id="@+id/song"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="告白气球"
            android:layout_toRightOf="@id/img"
            android:layout_marginTop="20dp"
            android:layout_marginLeft="20dp"
            android:textColor="#000"
            android:textSize="15sp"/>

        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="周杰伦"
            android:layout_toRightOf="@id/img"
            android:layout_marginTop="40dp"
            android:layout_marginLeft="20dp"
            android:textColor="#000"
            android:textSize="12sp"
          />
        <TextView
            android:id="@+id/time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="3:30"
            android:layout_centerVertical="true"
            android:layout_centerHorizontal="true"
            android:textColor="#000"
            android:textSize="12sp"
            />
        <TextView
            android:id="@+id/next"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="下一曲"
            android:textSize="12sp"
            android:textColor="#000"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="10dp"/>

        <TextView
            android:id="@+id/stop"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="暂停"
            android:textSize="12sp"
            android:textColor="#000"
            android:layout_toLeftOf="@id/next"
            android:layout_centerVertical="true"
            android:enabled="false"
            android:layout_marginRight="20dp"/>

        <TextView
            android:id="@+id/up"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="上一曲"
            android:textSize="12sp"
            android:textColor="#000"
            android:layout_toLeftOf="@id/stop"
            android:layout_centerVertical="true"
            android:layout_marginRight="20dp"/>
    </RelativeLayout>



</RelativeLayout>

2.写Bean类、Adapter适配器

package com.example.myapplication;

import java.io.Serializable;

public class VideoBean implements Serializable {

    private int id;
    private String song;
    private String singer;
    private String album;
    private String time;
    private int path;

    public VideoBean(int id, String song, String singer, String album, String time, int path) {
        this.id = id;
        this.song = song;
        this.singer = singer;
        this.album = album;
        this.time = time;
        this.path = path;
    }

    public String getTime() {
        return time;
    }

    public String getAlbum() {
        return album;
    }

    public int getId() {
        return id;
    }

    public int getPath() {
        return path;
    }

    public String getSinger() {
        return singer;
    }

    public String getSong() {
        return song;
    }
}

package com.example.myapplication;

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

import java.util.List;

public class VideoAdapter extends BaseAdapter {

    private List<VideoBean> list;
    private Context context;

    public VideoAdapter(List<VideoBean> list, Context context) {
        this.list = list;
        this.context = context;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView==null){
            convertView= LayoutInflater.from(context).inflate(R.layout.adaper_video,parent,false);
        }
        VideoBean bean=list.get(position);
        TextView id=convertView.findViewById(R.id.id);
        TextView song=convertView.findViewById(R.id.song);
        TextView singer=convertView.findViewById(R.id.singer);
        TextView album=convertView.findViewById(R.id.album);
        TextView time=convertView.findViewById(R.id.time);

        id.setText(bean.getId()+"");
        song.setText(bean.getSong());
        singer.setText(bean.getSinger());
        album.setText(bean.getAlbum());
        time.setText(bean.getTime());


        return convertView;
    }
}

3.写listview的子布局页面

<?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="match_parent"
    android:orientation="vertical">


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:background="@drawable/shape10"
        android:orientation="horizontal"
        android:paddingLeft="30dp"
        android:paddingRight="30dp">

        <TextView
            android:id="@+id/id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="1"
            android:textSize="35sp"
            android:textColor="#000"
          android:layout_centerVertical="true"/>

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:layout_centerVertical="true"
            android:layout_marginLeft="50dp"
            >
            <TextView
                android:id="@+id/song"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="告白气球"
                android:textSize="25sp"
                android:textColor="#000"
                android:layout_gravity="center"/>
            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                android:layout_marginTop="10dp">


            <TextView
                android:id="@+id/singer"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="许嵩"
                android:textSize="20sp"
                android:textColor="#000"
                android:layout_gravity="center"/>

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="|"
                    android:textSize="20sp"
                    android:textColor="#000"

                    android:layout_marginLeft="10dp"
                    android:layout_gravity="center"/>

                <TextView
                    android:id="@+id/album"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="专辑名称"
                    android:textSize="20sp"
                    android:textColor="#000"
                    android:layout_marginLeft="10dp"
                    android:layout_gravity="center"/>
            </LinearLayout>
        </LinearLayout>


        <TextView
            android:id="@+id/time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="18sp"
            android:layout_alignParentRight="true"
            android:text="4:20"
            android:textColor="#000"
            android:layout_alignParentBottom="true"
            android:layout_marginBottom="15dp"/>


    </RelativeLayout>

</LinearLayout>

下载几个mp3音乐导入raw中

4.编写主页面java文件

package com.example.myapplication;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.media.MediaParser;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;


public class MainActivity extends AppCompatActivity {

    private TextView song,name,next,stop,up,time;

    private ListView video_list;
    private List<VideoBean> data;

    private MediaPlayer mediaPlayer;

    private int num=0;
    private int id=0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();
        data=new ArrayList<>();
        data.add(new VideoBean(1,"七月上","Jam","七月上","3:10",R.raw.a1));
        data.add(new VideoBean(2,"大摇大摆迎春来","大张伟","七月上","2:54",R.raw.a2));
        data.add(new VideoBean(3,"抱歉","科德夏萍","陈慧琳","3:56",R.raw.a3));
        data.add(new VideoBean(4,"白色恋人","游鸿铭","游鸿铭","4:48",R.raw.a4));
        data.add(new VideoBean(4,"白色恋人","游鸿铭","游鸿铭","4:48",R.raw.a4));
        data.add(new VideoBean(4,"白色恋人","游鸿铭","游鸿铭","4:48",R.raw.a4));
        video_list.setAdapter(new VideoAdapter(data,MainActivity.this));
        video_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                    VideoBean bean=data.get(position);
                    song.setText(bean.getSong());
                    name.setText(bean.getSinger());
                    time.setText(bean.getTime());
            
                if (mediaPlayer != null) {
                    if (mediaPlayer.isPlaying()) {
                        mediaPlayer.stop();
                    }
                    mediaPlayer.release();
                    mediaPlayer = null;
                }
                  mediaPlayer=MediaPlayer.create(MainActivity.this,bean.getPath());
                  mediaPlayer.start();
                  stop.setEnabled(true);


            }
        });

        stop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                num++;
                if (num%2==1){
                    mediaPlayer.pause();
                    stop.setText("开始");
                }else if (num%2==0){
                    stop.setText("暂停");
                    mediaPlayer.start();
                }

            }
        });


        next.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                mediaPlayer.reset();

                id = (id % data.size()) + 1;
                if (id >= data.size()) {
                    id = 0;
                }
                VideoBean bean = data.get(id);
                song.setText(bean.getSong());
                name.setText(bean.getSinger());
                time.setText(bean.getTime());
                mediaPlayer = MediaPlayer.create(MainActivity.this, bean.getPath());
                mediaPlayer.start();
                // 恢复"暂停"按钮的文本，因为我们现在正在播放新的歌曲
                stop.setText("暂停");
                stop.setEnabled(true);
            }
        });


        up.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mediaPlayer.reset();
                id = id-1;
                // 如果索引超出了列表大小，将其重置为0（列表的第一首歌曲）
                if (id <0) {
                    id = data.size() - 1;
                }
                VideoBean bean = data.get(id);
                song.setText(bean.getSong());
                name.setText(bean.getSinger());
                time.setText(bean.getTime());
                mediaPlayer = MediaPlayer.create(MainActivity.this, bean.getPath());
                mediaPlayer.start();
                // 恢复"暂停"按钮的文本，因为我们现在正在播放新的歌曲
                stop.setText("暂停");
                stop.setEnabled(true);
            }
        });



    }
    private void init(){
        song=findViewById(R.id.song);
        name=findViewById(R.id.name);
        next=findViewById(R.id.next);
        stop=findViewById(R.id.stop);
        up=findViewById(R.id.up);
        time=findViewById(R.id.time);
        video_list=findViewById(R.id.video_list);

    }

}