教你轻松制作Android音乐播放器

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。