private ListView listView;listView = (ListView) view.findViewById(R.id.listview);

public class AudioListAdapter extends CursorAdapter{public AudioListAdapter(Context context, Cursor c) {super(context, c);}//设置需要显示的布局文件@Overridepublic View newView(Context context, Cursor cursor, ViewGroup parent) {return null;}//设置相关的数据的显示@Overridepublic void bindView(View view, Context context, Cursor cursor) {}}

4. 优化adapter并为其设置数据的显示

4.1 创建一个viewHolder

class ViewHolder{//这里是用于显示相关歌曲的名称与艺术家名称的控件，TextView mTitleTextView,mArtistTextView;public ViewHolder(View view){mTitleTextView = (TextView) view.findViewById(R.id.tv_title);mArtistTextView = (TextView) view.findViewById(R.id.tv_artist);}

private ViewHolder getHolder(View view){ViewHolder viewHolder = (ViewHolder) view.getTag();if(viewHolder==null){viewHolder = new ViewHolder(view);view.setTag(viewHolder);}return viewHolder;}

4.3 在adapter中使用viewHolder

public class AudioListAdapter extends CursorAdapter{public AudioListAdapter(Context context, Cursor c) {super(context, c);}@Overridepublic View newView(Context context, Cursor cursor, ViewGroup parent) {//设置显示音乐信息的列表内容return View.inflate(context, R.layout.adapter_audio_list, null);}ViewHolder holder;@Overridepublic void bindView(View view, Context context, Cursor cursor) {holder = getHolder(view);//这里是通过对象保存数据的方式将cursor中的数据取出并设置相关显示AudioItem audioItem = AudioItem.fromCursor(cursor);holder.mTitleTextView.setText(StringUtil.formatAudioName(audioItem.getTitle()));holder.mArtistTextView.setText(audioItem.getArtist());}}

public class AudioItem implements Serializable{private String title;private String artist;private String path;private long duration;//将cursor的数据封装于对象public static AudioItem fromCursor(Cursor cursor){AudioItem audioItem = new AudioItem();audioItem.setArtist(cursor.getString(cursor.getColumnIndex(Media.ARTIST)));audioItem.setDuration(cursor.getLong(cursor.getColumnIndex(Media.DURATION)));audioItem.setPath(cursor.getString(cursor.getColumnIndex(Media.DATA)));audioItem.setTitle(cursor.getString(cursor.getColumnIndex(Media.DISPLAY_NAME)));return audioItem;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public String getArtist() {return artist;}public void setArtist(String artist) {this.artist = artist;}public String getPath() {return path;}public void setPath(String path) {this.path = path;}public long getDuration() {return duration;}public void setDuration(long duration) {this.duration = duration;}}

    private AudioListAdapter mAudioAdapter;mAudioAdapter = new AudioListAdapter(getActivity(), null);

   listView.setAdapter(adapter);

7 查询数据并将数据传输给mAudioAdapter

private SimpleQueryHandler queryHandler;queryHandler = new SimpleQueryHandler(getActivity().getContentResolver());//查询的音乐相关的信息String[] projection = {Media._ID,Media.DISPLAY_NAME,Media.ARTIST,Media.DATA,Media.DURATION};//数据查询queryHandler.startQuery(0, adapter, Media.EXTERNAL_CONTENT_URI, projection, null, null, null);

8 使用到的相关查询辅助类

    public class SimpleQueryHandler  extends AsyncQueryHandler{public SimpleQueryHandler(ContentResolver cr) {super(cr);}@Overrideprotected void onQueryComplete(int token, Object cookie, Cursor cursor) {super.onQueryComplete(token, cookie, cursor);if(cookie!=null && cookie instanceof CursorAdapter){CursorAdapter adapter = (CursorAdapter) cookie;adapter.changeCursor(cursor);//相当于notify}}}

public class AudioPlayerActivity extends  Activity{}

在这里设置自定的播放音乐的显示页面

//当前点击要播放的位置int currentPosition = getIntent().getExtras().getInt("currentPosition");//所有音乐信息的集合ArrayList<AudioItem> audioList = (ArrayList<AudioItem>) getIntent().getExtras().getSerializable("audioList");

11 这里使用的是后台可以进行音乐播放，那么就需要使用到与服务的交互

创建用于播放音乐的服务并进行清单文件中的注册

public class AudioPlayService extends Service{private AudioServiceBinder audioServiceBinder;@Overridepublic IBinder onBind(Intent intent) {return audioServiceBinder;}}@Overridepublic void onCreate() {super.onCreate();audioServiceBinder = new AudioServiceBinder();}//数据相关的绑定操作public class AudioServiceBinder extends Binder{}}

Intent intent = new Intent(this,AudioPlayService.class);Bundle bundle = new Bundle();//传输的数据int currentPosition = getIntent().getExtras().getInt("currentPosition");ArrayList<AudioItem> audioList = (ArrayList<AudioItem>) getIntent().getExtras().getSerializable("audioList");//数据封装bundle.putInt("currentPosition", currentPosition);bundle.putSerializable("audioList", audioList);intent.putExtras(bundle);//服务绑定serviceConnection = new AudioServiceConnection();bindService(intent, serviceConnection, Service.BIND_AUTO_CREATE);startService(intent);//为了给service传递数据

class AudioServiceConnection implements ServiceConnection{//当服务连接的时候会调用这个方法@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {}//当服务断开时候会调用这个方法@Overridepublic void onServiceDisconnected(ComponentName name) {}}

13 activity 与 service方法的交互

在activity中 通过 serviceConnection 来获取 服务 AudioPlayService 中的AudioServiceBinder
这样我们就可以通过AudioServiceBinder这个对象来进行activity与service中方法的交互

private AudioServiceBinder audioServiceBinder;class AudioServiceConnection implements ServiceConnection{//当服务连接的时候会调用这个方法，那么可以在这个方法中获取binder的对象（通过它来操作服务中的相关方法）@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {audioServiceBinder = (AudioServiceBinder) service;}//当服务断开时候会调用这个方法@Overridepublic void onServiceDisconnected(ComponentName name) {}}

    首先获取传递的数据 复写service的方法 onStartCommand  来获取传递的数据 private int currentPosition;private ArrayList<AudioItem> audioList;private AudioServiceBinder audioServiceBinder ;@Overridepublic void onCreate() {super.onCreate();audioServiceBinder = new AudioServiceBinder();}@Overridepublic int onStartCommand(Intent intent, int flags, int startId) {//获取数据currentPosition = intent.getExtras().getInt("currentPosition");audioList = (ArrayList<AudioItem>) intent.getExtras().getSerializable("audioList");//设置音乐播放audioServiceBinder.playAudio();return START_STICKY;//如果服务被杀死，会自动重启}在AudioServiceBinder 中设置与播放音乐相关的操作逻辑 设置播放音乐的操作方法 public class AudioServiceBinder extends Binder{/*** 播放音乐*/public void playAudio(){//判断一下是否有音乐资源if(audioList==null || audioList.size()==0)return;if(mediaPlayer!=null){mediaPlayer.release();mediaPlayer = null;}AudioItem audioItem = audioList.get(currentPosition);//创建mediaPlayer对象mediaPlayer = new MediaPlayer();//设置相关的监听mediaPlayer.setOnPreparedListener(mOnPreparedListener);mediaPlayer.setOnCompletionListener(mOnCompletionListener);//设置数据源try {mediaPlayer.setDataSource(audioItem.getPath());mediaPlayer.prepareAsync();} catch (IllegalArgumentException e) {e.printStackTrace();} catch (SecurityException e) {e.printStackTrace();} catch (IllegalStateException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}//创建相关的加载播放监听 并设置音乐的播放private OnPreparedListener mOnPreparedListener = new OnPreparedListener() {@Overridepublic void onPrepared(MediaPlayer mp) {mediaPlayer.start();}};private OnCompletionListener mOnCompletionListener = new OnCompletionListener() {@Overridepublic void onCompletion(MediaPlayer mp) {}};}

15 在服务中通过发送广播通知Activity中更新页面显示数据

定义我们用到的广播接收者

class AudioServiceReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {}}

在activity的OnCreate方法中进行注册

/*** 注册AudioService中的广播接受者*/private void registerAudioServiceReceiver() {receiver = new AudioServiceReceiver();IntentFilter filter = new IntentFilter(AudioPlayService.ACTION_NOTIFY_PREPARED);//参数是广播接收的标识//filter.addAction(AudioPlayService.ACTION_COMPLATION); 这里可以添加多个活动registerReceiver(receiver, filter);}

在服务中，当音乐开始进行播放的时候，发送广播，并将音乐的信息发给activity中

private void notifyPrepared(){Intent intent = new Intent(ACTION_NOTIFY_PREPARED);intent.putExtra("audioItem", audioList.get(currentPosition));//这里面就是携带的数据sendBroadcast(intent);}

当广播发送后，我们在对应的广播接收者中进行消息的接收

class AudioServiceReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {if (AudioPlayService.ACTION_NOTIFY_PREPARED.equarrayLists(intent.getAction())) {AudioItem audioItem = (AudioItem) intent.getSeriarrayListizableExtra("audioItem");} else if (AudioPlayService.ACTION_COMPLATION.equarrayLists(intent.getAction())) {}}}