疯狂Android讲义源码10章 part2

/** * */ package org.crazyit.broadcast; 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; /** * Description: * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a> * <br/>Copyright (C), 2001-2012, Yeeku.H.Lee * <br/>This program is protected by copyright laws. * <br/>Program Name: * <br/>Date: * @author Yeeku.H.Lee kongyeeku@163.com * @version 1.0 */ public class MusicService extends Service { MyReceiver serviceReceiver; AssetManager am; String[] musics = new String[]{ "wish.mp3", "promise.mp3", "beautiful.mp3" }; MediaPlayer mPlayer; //当前的状态,0x11 代表没有播放 ；0x12代表 正在播放；0x13代表暂停 int status = 0x11; // 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(MusicBox.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() { @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(MusicBox.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) { int control = intent.getIntExtra("control", -1); switch (control) { // 播放或暂停 case 1: // 原来处于没有播放状态 if (status == 0x11) { // 准备、并播放音乐 prepareAndPlay(musics[current]); status = 0x12; } // 原来处于播放状态 else if (status == 0x12) { // 暂停 mPlayer.pause(); // 改变为暂停状态 status = 0x13; } // 原来处于暂停状态 else if (status == 0x13) { // 播放 mPlayer.start(); // 改变状态 status = 0x12; } break; // 停止声音 case 2: // 如果原来正在播放或暂停 if (status == 0x12 || status == 0x13) { // 停止播放 mPlayer.stop(); status = 0x11; } } /* 发送广播通知Activity更改图标、文本框 */ Intent sendIntent = new Intent(MusicBox.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(); } } }