欣赏一下我们清爽的界面吧~

如果是只用activity来制作这样的东西简直是太小儿科了，此处我们当然用的是service
首先我们先上service的代码：
1、如果我们要访问service的属性和方法，那么在activity肯定是以bindservice的方法实现的，而在service中的onbind方法也是必须要实现的，onbind返回的Ibinder对象在activity的serviceconnection中得到使用。
2、activity获取到Ibinder对象，可以进一步获取服务对象和player对象，来进行访问。
3、Environment.getExternalStorageDirectory()是获取sd中的内容的，不管是手机出场就已经内置的sd卡，还是用户后来自己添加的sd卡；而getExternalFilesDir()获取的真正是手机内部的存储空间，，/data/data/your_package/，随着应用的卸载存储的文件会被删除。
4、service通过发送广播与activity进行界面交互

public class MusicService extends Service{ private List<File> musicList; private MediaPlayer player; private int curPage; public static final String MFILTER = "broadcast.intent.action.text"; public static final String NAME = "name"; public static final String TOTALTIME = "totaltime"; public static final String CURTIME = "curtime"; @Override public IBinder onBind(Intent intent) {//1  // TODO Auto-generated method stub  return new MBinder(); } public class MBinder extends Binder{//2  public MusicService getService(){   return MusicService.this;  }   public MediaPlayer getPlayer(){   return player;  } } @Override public void onCreate() {  // TODO Auto-generated method stub  super.onCreate();  musicList = new ArrayList<File>();  File rootDir = Environment.getExternalStorageDirectory();//3  Log.d("rootname",rootDir.getName());  Log.d("rootname",rootDir.getAbsolutePath());  fillMusicList(rootDir);  Log.d("musiclist",String.valueOf(musicList.size()));  player = new MediaPlayer();  if (musicList.size() != 0) {   startPlay();  }    player.setOnCompletionListener(new OnCompletionListener() {      @Override   public void onCompletion(MediaPlayer mp) {    // TODO Auto-generated method stub    player.reset();    curPage = curPage==musicList.size()-1? (curPage+1)%musicList.size() : curPage+1;     startPlay();   }  }); } /*迭代获取 音乐 文件*/ private void fillMusicList(File dir){  File[] sourceFiles = dir.listFiles();  Log.d("长度",String.valueOf(sourceFiles.length));  for(File file : sourceFiles){   if (file.isDirectory()) {    Log.d("文件夹名称",String.valueOf(file.getName()));//    if (!file.getName().equals("lost+found")) {     fillMusicList(file);//    }       }    else {     String name = file.getName();     Log.d("childname",file.getName());     if (name.endsWith(".mp3")||name.endsWith(".acc")) {//支持的格式      musicList.add(file);     }   }  } } private void startPlay(){  mSendBroadCast(NAME,musicList.get(curPage).getName());//4  try {   player.setDataSource(musicList.get(curPage).getAbsolutePath());   player.prepare();   player.start();   player.getDuration();   mSendBroadCast(TOTALTIME,player.getDuration());   Timer timer = new Timer();   timer.schedule(new TimerTask() {        @Override    public void run() {     // TODO Auto-generated method stub     mSendBroadCast(CURTIME,player.getCurrentPosition());    }   },0,1000);     } catch (IllegalArgumentException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } catch (SecurityException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } catch (IllegalStateException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } catch (IOException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } } public void playNext(){  curPage = curPage==musicList.size()-1? (curPage+1)%musicList.size() : curPage+1;   Log.d("curpage",String.valueOf(curPage));  player.reset();  startPlay(); } public void playPrevious(){  curPage = curPage==0? 0 : curPage-1;   Log.d("curpage",String.valueOf(curPage));  player.reset();  startPlay(); } public void parse(){  player.pause(); } public void restart(){  player.start(); } private void mSendBroadCast(String key, String value){  Intent intent = new Intent(MFILTER);  intent.putExtra(key,value);//发送广播  sendBroadcast(intent); }  private void mSendBroadCast(String key, int value){  Intent intent = new Intent(MFILTER);  intent.putExtra(key,value);//发送广播  sendBroadcast(intent); }}

接下来上activity代码：
1、通过Ibinder对象获取服务对象
2、获取到服务对象以后，再访问服务的方法。
3、通过receiver刷新页面

public class MainActivity extends Activity implements OnClickListener{ SeekBar seekBar; TextView curTime,totalTime; TextView title;  private ServiceConnection sc; private MusicService ms; private boolean isStop; private double totalTimeInt;  @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  IntentFilter filter = new IntentFilter(MusicService.MFILTER);  registerReceiver(new MusicReceiver(),filter);  sc = new ServiceConnection() {      @Override   public void onServiceDisconnected(ComponentName name) {    // TODO Auto-generated method stub    ms = null;   }      @Override   public void onServiceConnected(ComponentName name, IBinder service) {    // TODO Auto-generated method stub    ms = ((MBinder)service).getService();//1       }  };  Button previous = (Button) findViewById(R.id.previous);  Button next = (Button) findViewById(R.id.next);  Button stop = (Button) findViewById(R.id.stop);  Button stopService = (Button) findViewById(R.id.stopService);  seekBar = (SeekBar) findViewById(R.id.mSeekbar);  curTime = (TextView) findViewById(R.id.curTime);  totalTime = (TextView) findViewById(R.id.totalTime);  title = (TextView) findViewById(R.id.title);    previous.setOnClickListener(this);  next.setOnClickListener(this);  stop.setOnClickListener(this);  stopService.setOnClickListener(this); } @Override public void onClick(View v) {  // TODO Auto-generated method stub  switch (v.getId()) {  case R.id.previous:   ms.playPrevious();//2   break;  case R.id.next:   ms.playNext();   break;  case R.id.stop:   if (isStop) {    ms.restart();   }   else {    ms.parse();   }   isStop = !isStop;   break;  case R.id.stopService:   Intent intent = new Intent("com.intent.musicplayer.MusicService");   unbindService(sc);   stopService(intent);   break;  default:   break;  } } @Override protected void onStart() {  // TODO Auto-generated method stub  super.onStart();  Intent intent = new Intent("com.intent.musicplayer.MusicService");  bindService(intent,sc,Context.BIND_AUTO_CREATE);//当然你可以用startService的方式启动服务，这样结束了activity以后并不会结束service   } private String transferMilliToTime(int millis){  DateFormat format = new SimpleDateFormat("mm:ss");  String result = format.format(new Date(millis));  return result; } private class MusicReceiver extends BroadcastReceiver{//3  @Override  public void onReceive(Context context, Intent intent) {   // TODO Auto-generated method stub   if (intent.getIntExtra(MusicService.CURTIME,0)!=0) {    double curTimeInt = intent.getIntExtra(MusicService.CURTIME,0);    curTime.setText(transferMilliToTime((int)curTimeInt));    double result = curTimeInt/totalTimeInt*100;    seekBar.setProgress((int) Math.floor(result));       }   else if(intent.getIntExtra(MusicService.TOTALTIME,0)!=0) {    totalTimeInt = intent.getIntExtra(MusicService.TOTALTIME,0);    totalTime.setText(transferMilliToTime((int)(totalTimeInt)));   }   else if (!TextUtils.isEmpty(intent.getStringExtra(MusicService.NAME))) {    title.setText(intent.getStringExtra(MusicService.NAME));   }  }   }}

4、最后附上xml布局文件，算是代码上传完全了：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="${relativePackage}.${activityClass}" > <TextView   android:id="@+id/title"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_gravity="center_horizontal"  android:textSize="25sp"  android:textColor="#444444"  /> <SeekBar   android:id="@+id/mSeekbar"  android:layout_gravity="center_horizontal"  android:layout_width="400dp"  android:layout_height="wrap_content"  android:max="100"  /> <RelativeLayout   android:layout_width="match_parent"  android:layout_height="wrap_content"  >  <TextView  android:id="@+id/curTime"  android:layout_height="wrap_content"  android:layout_width="wrap_content"  android:layout_alignParentLeft="true"    />  <TextView  android:id="@+id/totalTime"  android:layout_height="wrap_content"  android:layout_width="wrap_content"  android:layout_alignParentRight="true"  /> </RelativeLayout> <RelativeLayout   android:layout_width="match_parent"  android:layout_height="wrap_content"  >  <Button  android:id="@+id/previous"  android:layout_height="wrap_content"  android:layout_width="wrap_content"  android:text="上一曲"  android:layout_alignParentLeft="true"  />  <Button    android:id="@+id/stop"   android:layout_height="wrap_content"   android:layout_width="wrap_content"   android:text="停止音乐"   android:layout_toRightOf="@id/previous"   />  <Button  android:id="@+id/next"  android:layout_height="wrap_content"  android:layout_width="wrap_content"  android:text="下一曲"  android:layout_alignParentRight="true"  />   <Button    android:id="@+id/stopService"   android:layout_height="wrap_content"   android:layout_width="wrap_content"   android:text="停止音乐服务"   android:layout_toLeftOf="@id/next"   /> </RelativeLayout> </LinearLayout>

以上就是制作Android音乐播放器的全部代码，希望对大家的学习有所帮助。