音乐播放器简单实现

使用Service实现音乐播放器

1.首先创一个Service类 代码如下

package com.example.myapplication5;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.util.Log;

import java.io.IOException;

public class MyService extends Service {
    
    
    MediaPlayer mediaPlayer;

    @Override
    public void onCreate() {
    
    
        super.onCreate();
        mediaPlayer = new MediaPlayer();
    }

    public MyService() {
    
    
    }

    @Override
    public IBinder onBind(Intent intent) {
    
    
        return new Binder();
    }

    class Binder extends android.os.Binder {
    
    

        public void start() {
    
    
            startmusic();
        }

        public void stop() {
    
    
            stopmusic();
        }
    }

    private void startmusic() {
    
    
        Log.e("---", "aaa");
        mediaPlayer.reset(); // 重置播放状态
        try {
    
    
            mediaPlayer.setDataSource("http://vfx.mtime.cn/Video/2019/03/12/mp4/190312083533415853.mp4");
            mediaPlayer.prepareAsync();  // 异步准备
            mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
    
      // 异步监听
                @Override
                public void onPrepared(MediaPlayer mediaPlayer) {
    
    
                    // 下载完成  播放
                    mediaPlayer.start();
                }
            });
        } catch (IOException e) {
    
    
            e.printStackTrace();
        }
    }

    private void stopmusic() {
    
    
        mediaPlayer.stop();
    }
}

2.然后在清单文件加入服务

        <service
            android:name=".MyService"
            android:enabled="true"
            android:exported="true">
        </service>

3.然后在Mactivity.java里面写实现代码

package com.example.myapplication5;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {
    
    
    MyService.Binder binder;
    private Button startmusic;
    private Button stopmusic;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        startmusic = (Button) findViewById(R.id.startmusic);
        stopmusic = (Button) findViewById(R.id.stopmusic);

        initService();
        /**
         *
         *  开始播放
         */
        startmusic.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                binder.start();
            }
        });

        /**
         *  暂停
         */

        stopmusic.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                binder.stop();
            }
        });
    }


    public void initService() {
    
    

        requestPermissions(new String[]{
    
    
                "android.permission.WRITE_EXTERNAL_STORAGE",
                "android.permission.READ_EXTERNAL_STORAGE"
        }, 99);


        ServiceConnection serviceConnection = new ServiceConnection() {
    
    
            @Override
            public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
    
    
                binder = (MyService.Binder) iBinder;
            }

            @Override
            public void onServiceDisconnected(ComponentName componentName) {
    
    

            }
        };
        bindService(new Intent(MainActivity.this, MyService.class), serviceConnection, BIND_AUTO_CREATE);
    }
}

4.main里面的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="播放"
        android:id="@+id/startmusic"
        />
  <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="暂停"
        android:id="@+id/stopmusic"
        />

</LinearLayout>