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一丶前端布局

Layout的框架

一个自定义的音乐播放器，页面布局大致如下

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二丶Activity

首先定义控件

    // 获取界面中显示歌曲标题、作者文本框TextView title, author;// 喜欢，播放，暂停，停止按钮ImageButton like, play, stop, previous, next;//进度条TextView currentTv;  //当前时间TextView totalTv;    //歌曲总时间int totalTime;       //歌曲总时长，用于获取歌曲时长SeekBar jindutiaoSb; //进度条int position;        //位置

定义音乐的状态，歌曲的名字和详情

	public static final String CTL_ACTION ="org.pyp.action.CTL_ACTION";public static final String UPDATE_ACTION ="org.pyp.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[]{"晴天—周杰伦", "奇妙能力歌", "我很好"};String[] authorStrs = new String[]{"从前有个人爱你很久很久","我拒绝更好更圆的月亮","只是偶尔遗憾会从眼泪掉"};

绑定按钮

		play = (ImageButton) this.findViewById(R.id.play);stop = (ImageButton) this.findViewById(R.id.stop);like = findViewById(R.id.like);previous = findViewById(R.id.previous);next = findViewById(R.id.next);//文本显示title = (TextView) findViewById(R.id.title);author = (TextView) findViewById(R.id.author);

添加监听

        // 为按钮的单击事件添加监听器like.setOnClickListener(this);play.setOnClickListener(this);stop.setOnClickListener(this);previous.setOnClickListener(this);next.setOnClickListener(this); 

自定义的BroadcastReceiver，负责监听从Service传回来的广播

	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);// 获取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;}}

定义点击事件，点击时创建Intent，发送广播，将被Service组件中的BroadcastReceiver接收到

public void onClick(View source) {// 创建IntentIntent intent = new Intent("org.pyp.action.CTL_ACTION");switch (source.getId()) {// 按下喜欢case R.id.like:if (flag) {like.setImageResource(R.drawable.unlike);flag = false;} else {like.setImageResource(R.drawable.like);flag = true;}break;// 按下播放/暂停按钮case R.id.play:intent.putExtra("control", 1);break;// 按下停止按钮case R.id.stop:intent.putExtra("control", 2);break;// 按下上一首case R.id.previous:intent.putExtra("control", 3);break;// 按下下一首case R.id.next:intent.putExtra("control", 4);break;}// 发送广播，将被Service组件中的BroadcastReceiver接收到sendBroadcast(intent);}

三丶Service

创建MediaPlayer，绑定监听器

        mPlayer = new MediaPlayer();mPlayer.setOnCompletionListener(new OnCompletionListener() // ①{@Overridepublic 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]);}});

定义MyReceiver，BroadcastReceiver接收广播

	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;}//上一首case 3:// 如果原来正在播放或暂停if (status == 0x12 || status == 0x13) {mPlayer.stop();if (current - 1 < 0) {current = musics.length - 1;} else {current--;}prepareAndPlay(musics[current]);status = 0x12;}break;//下一首case 4:if (status == 0x12 || status == 0x13) {mPlayer.stop();if (current + 1 >= musics.length) {current = 0;} else {current++;}prepareAndPlay(musics[current]);status = 0x12;}break;}// 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);}

播放音乐的方法

	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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实验演示

git仓库地址.