Android学习笔记(七) 音乐播放器 Service实现

关于Service

推荐

http://blog.csdn.net/Android_Tutor/archive/2010/08/04/5789203.aspx 

 

 

关于binder机制

推荐

http://blog.csdn.net/maxleng/archive/2010/04/15/5490770.aspx

 

 

 

//下面是MusicPlayer用Service实现

 

//MyService.java

package young.MyService;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.Map;import android.app.Activity;import android.app.Service;import android.content.ComponentName;import android.content.Context;import android.content.Intent;import android.content.ServiceConnection;import android.os.Bundle;import android.os.IBinder;import android.view.ContextMenu;import android.view.View;import android.view.View.OnClickListener;import android.widget.AdapterView;import android.widget.Button;import android.widget.ListView;import android.widget.SimpleAdapter;import android.widget.AdapterView.OnItemClickListener;public class MyService extends Activity implements OnClickListener,OnItemClickListener {private MusicService musicService;private Context myContext;private Button btnSynchro , btnStop , btnRestart , btnPause;private ListView songsListView;private ArrayList<Map<String, Object>> songs ;//在bindService时会启动他 private ServiceConnection mServiceConnection = new ServiceConnection() { public void onServiceConnected(ComponentName name, IBinder service) { // TODO Auto-generated method stub musicService = ((MusicService.MyBinder)service).getService(); } public void onServiceDisconnected(ComponentName name) { // TODO Auto-generated method stub } }; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //启动服务 Intent i = new Intent(); i.setClass(MyService.this, MusicService.class); //bindService启动的Service在Activity关闭时不会关闭，start会关闭 bindService(i, mServiceConnection, BIND_AUTO_CREATE); initView(); } private void initView(){ songsListView = (ListView)findViewById(R.id.music_list); songsListView.setOnItemClickListener(this); btnSynchro = (Button)findViewById(R.id.synchro); btnSynchro.setOnClickListener(this); btnPause = (Button)findViewById(R.id.pause); btnPause.setOnClickListener(this); btnStop = (Button)findViewById(R.id.stop); btnStop.setOnClickListener(this); btnRestart = (Button)findViewById(R.id.restart); btnRestart.setOnClickListener(this); }public void onClick(View v) {// TODO Auto-generated method stubif (v==btnSynchro) {try {songs = musicService.synchro();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}SimpleAdapter ladapter = new SimpleAdapter( this, songs, R.layout.relative, new String[]{"FileName","Path"}, new int[]{R.id.Name,R.id.Path} );songsListView.setAdapter(ladapter);}if(v==btnPause) musicService.pauseMusic();if(v==btnRestart)musicService.restartMusic();if(v==btnStop)musicService.stopMusic();}public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {// TODO Auto-generated method stubHashMap<String, Object> o = (HashMap<String, Object>) arg0.getItemAtPosition(position);try {musicService.playMusic(o.get("Path").toString());} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} } 

 

//MusicService

 

package young.MyService;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.Map;import android.app.Service;import android.content.Intent;import android.media.MediaPlayer;import android.media.MediaPlayer.OnCompletionListener;import android.os.Binder;import android.os.IBinder;public class MusicService extends Service{private MyBinder binder ;private MediaPlayer musicPlayer;private static ArrayList<File> musicLibrary =null; @Overridepublic IBinder onBind(Intent intent) {// TODO Auto-generated method stubbinder = new MyBinder();return binder;}@Overridepublic void onCreate() {super.onCreate();}@Overridepublic void onStart(Intent intent, int startId) {super.onStart(intent, startId);}@Overridepublic void onDestroy() {super.onDestroy();}//恢复播放public void restartMusic(){if(musicPlayer == null)return ;if(!musicPlayer.isPlaying()){musicPlayer.start();}}////暂停播放public void pauseMusic(){if(musicPlayer == null)return ;if(musicPlayer.isPlaying()) musicPlayer.pause();}//停止播放public void stopMusic(){if(musicPlayer == null)return ;if(musicPlayer.isPlaying()) musicPlayer.stop();}//播放一首音乐public void playMusic(String path) throws IOException{if(musicPlayer == null)musicPlayer = new MediaPlayer();if(musicPlayer.isPlaying())musicPlayer.stop(); try{ musicPlayer.reset(); musicPlayer.setDataSource(path); musicPlayer.prepare(); musicPlayer.start(); }catch (IllegalArgumentException e) { // handle exception e.printStackTrace(); } catch (IllegalStateException e) { // handle exception e.printStackTrace(); } musicPlayer.setOnCompletionListener(new OnCompletionListener() {public void onCompletion(MediaPlayer mp) {// TODO Auto-generated method stubmp.release();}});}/** * * @return * @throws IOException */public ArrayList<Map<String, Object>> synchro() throws IOException{musicLibrary = new ArrayList<File>();getAllFiles(new File("/sdcard"));return getMapData(musicLibrary);}/** * * @param root * @throws IOException */private void getAllFiles(File root) throws IOException{File files[] = root.listFiles();if(files != null)for(File f:files){if(f.isDirectory()){getAllFiles(f);}else{//检查文件类型String fpath = f.getPath().substring(f.getPath().lastIndexOf(".")+1,f.getPath().length());if(fpath.equals("mp3")){musicLibrary.add(f);}}} }/** * 这个函数返回<Map<String, Object>>类型的musicLibrary 用于作为listView数据源 * @param list * @return */private ArrayList<Map<String, Object>> getMapData(ArrayList<File> list){ ArrayList<Map<String, Object>> data = new ArrayList<Map<String, Object>>(); HashMap<String,Object> item; int i = 0 ; for(i=0;i<list.size();i++){ item = new HashMap<String,Object>(); String path = list.get(i).toString(); String name = path.substring(path.lastIndexOf("/")+1,path.length()); //保存每一格list单元格的数据 ， item.put("FileName",name); item.put("Path", path); data.add(item); } return data; }public class MyBinder extends Binder{ MusicService getService() { return MusicService.this; } } } 

 

记得在Mainfest中注册Service