用service做的音乐播放

来源：互联网发布：数据修炼系统笔趣阁编辑：程序博客网时间：2024/05/01 17:02

1：AndroidManifest.xml中的service

2：前台的JAVA类：

[java] view plaincopyprint?
package WangLi.Service.MusicBox;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.TextView;

public class MusicBox extends Activity implements OnClickListener {
    // 获取界面中显示歌曲标题，作者文本框
    TextView title, author;
    // 播放,暂停按钮
    ImageButton play, stop;
    ActivityReceiver activityReceiver;
    public static final String CTL_ACTION = "CTL_ACTION";
    public static final String UPDATE_ACTION = "UPDATE_ACTION";
    // 定义音乐的播放状态，0x11代表没有播放；0x12代表正在播放；0x13代表暂停
    int status = 0x11;
    String[] titleStrs = new String[] { "心愿", "约定", "美丽新世界" };
    String[] authorStrs = new String[] { "未知艺术家", "周蕙", "伍佰" };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // 获取程序界面中的两个按钮
        play = (ImageButton) findViewById(R.id.play);
        stop = (ImageButton) findViewById(R.id.stop);
        title = (TextView) findViewById(R.id.title);
       author = (TextView) findViewById(R.id.author);
        // 为两个按钮的单击事件添加监听器
        play.setOnClickListener(this);
        stop.setOnClickListener(this);
        activityReceiver = new ActivityReceiver();
        // 创建IntentFilter
        IntentFilter filter = new IntentFilter();
        // 指定BroadcastReceiver监听的Action
        filter.addAction(UPDATE_ACTION);
       // 注册BroadcastReceiver
        registerReceiver(activityReceiver, filter);
        Intent intent = new Intent(this, MusicService.class);
        // 启动后台Service
        startService(intent);
    }

    @Override
    public void onClick(View source) {
        // 创建Intent
        Intent intent = new Intent("CTL_ACTION");
        switch (source.getId()) {
        // 按下播放/暂停按钮
        case R.id.play:
            intent.putExtra("control", 1);
            break;
        case R.id.stop:
            intent.putExtra("control", 2);
            break;
        }
        sendBroadcast(intent);
    }

    // 自定义的BroadcastReceiver，负责监听从Service传回来的广播
   public class ActivityReceiver extends BroadcastReceiver {
       @Override
      public void onReceive(Context context, Intent intent) {
           // 获取Intent中的update消息,update代表播放状态
           int update = intent.getIntExtra("update", -1);
            // 攻取Intent中的current消息,current代表当前正在播放的歌曲
            int current = intent.getIntExtra("current", -1);
            if (current >= 0) {
                title.setText(titleStrs[current]);
                author.setText(authorStrs[current]);
            }
            switch (update) {
            case 0x11:
                play.setImageResource(R.drawable.play);
                status = 0x11;
                break;
            // 控制系统进入播放状态
            case 0x12:
                // 播放状态下设置使用暂停图标
                play.setImageResource(R.drawable.pause);
                // 设置当前状态
                status = 0x12;
                break;
            // 控制系统进入暂停状态
            case 0x13:
                // 暂停状态下设置使用播放图标
                play.setImageResource(R.drawable.play);
                // 设置当前状态
                status = 0x13;
                break;
            }
        }
    }
}
3：后台service控制的JAVA类：

package com.example.musicproject;

import java.io.IOException;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.AssetFileDescriptor;
import android.content.res.AssetManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.IBinder;

public class MusicService extends Service
{
    //广播
    MyReceiver serviceReceiver;
    AssetManager am;
    String[] musics = new String[] { "pfzl.mp3", "xws.mp3",
        "zzlfz.mp3" };
    MediaPlayer mPlayer;
    // 当前的状态,1 代表没有播放；2代表正在播放；3代表暂停
    int status = 1;
    // 记录当前正在播放的音乐
    int current = 0;

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

    @Override
    public void onCreate()
    {
        am = getAssets();
        // 创建BroadcastReceiver
        serviceReceiver = new MyReceiver();
        // 创建IntentFilter
        IntentFilter filter = new IntentFilter();
        filter.addAction(MainActivity.CTL_ACTION);
        registerReceiver(serviceReceiver, filter);
        // 创建MediaPlayer
        mPlayer = new MediaPlayer();
        // 为MediaPlayer播放完成事件绑定监听器
        mPlayer.setOnCompletionListener(new OnCompletionListener() //①
        {
            @Override
            public void onCompletion(MediaPlayer mp)
            {
                current++;
                if (current >= 3)
                {
                    current = 0;
                }
                // 发送广播通知Activity更改文本框
                Intent sendIntent = new Intent(MainActivity.UPDATE_ACTION);
                sendIntent.putExtra("current", current);
                // 发送广播，将被Activity组件中的BroadcastReceiver接收到
                sendBroadcast(sendIntent);
                // 准备、并播放音乐
                prepareAndPlay(musics[current]);
            }
        });
        super.onCreate();
    }

    public class MyReceiver extends BroadcastReceiver
    {
        @Override
        public void onReceive(final Context context, Intent intent)
        {
            //接收发送来的广播数据
            int control = intent.getIntExtra("control", -1);
            switch (control)
            {
                // 播放或暂停,判断上一次的状态
                case 1:
                    // 原来处于没有播放状态
                    if (status == 1)
                    {
                        // 准备、并播放音乐
                        prepareAndPlay(musics[current]);
                        status = 2;
                    }
                    // 原来处于播放状态
                    else if (status == 2)
                    {
                        // 暂停
                        mPlayer.pause();
                        // 改变为暂停状态
                        status = 3;
                    }
                    // 原来处于暂停状态
                    else if (status == 3)
                    {
                        // 播放
                        mPlayer.start();
                        // 改变状态
                        status = 2;
                    }
                    break;
                // 停止声音
                case 2:
                    // 如果原来正在播放或暂停
                    if (status == 2 || status == 3)
                    {
                        // 停止播放
                        mPlayer.stop();
                        status = 1;
                    }
            }
            // 发送广播通知Activity更改图标、文本框
            Intent sendIntent = new Intent(MainActivity.UPDATE_ACTION);
            sendIntent.putExtra("update", status);
            sendIntent.putExtra("current", current);
            // 发送广播，将被Activity组件中的BroadcastReceiver接收到
            sendBroadcast(sendIntent);
        }
    }

    private void prepareAndPlay(String music)
    {
        try
        {
            // 打开指定音乐文件
            AssetFileDescriptor afd = am.openFd(music);
            mPlayer.reset();
            // 使用MediaPlayer加载指定的声音文件。
            mPlayer.setDataSource(afd.getFileDescriptor(),
                afd.getStartOffset(), afd.getLength());
            // 准备声音
            mPlayer.prepare();
            // 播放
            mPlayer.start();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

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