如何從android中的Cursor播放歌曲？

我做了一個簡單的應用程序，顯示歌曲列表，並計劃讓每個列表項目點擊時播放歌曲。然而，我已經設置了一切，音樂不會開始播放。我將如何使用MediaPlayer播放ContentResolver中的歌曲？我已經設置了一個示例代碼供您查看。如果可能的話，有一些樣品或例子會很榮幸。如何從android中的Cursor播放歌曲？

public class MainActivity extends ActionBarActivity { 
    List tracks; 
    String[] ColId; 
    List<Track>tack; 
    private MediaPlayer mMediaPlayer; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
    } 


    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.menu_main, menu); 
     tracks = Track.getItems(this); 
     ColId = Track.COLUMNS; 

     ListView trackList = (ListView)findViewById(R.id.listView); 
     ListTrackAdapter adapter = new ListTrackAdapter(this, tracks); 

     trackList.setAdapter(adapter); 

     trackList.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 



       //long //id = 0;/* retrieve it from somewhere */; 
       Uri contentUri = ContentUris.withAppendedId(
         android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, position); 


       try { 
        mMediaPlayer = new MediaPlayer(); 
        mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); 
        mMediaPlayer.setDataSource(MainActivity.this, contentUri); 
        mMediaPlayer.prepare(); 
        mMediaPlayer.start(); 



       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
       String pos = String.valueOf(tracks.get(position)); 
       Toast.makeText(MainActivity.this,position+" = "+ColId[0],Toast.LENGTH_SHORT).show(); 

      } 
     }); 


     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    @Override 
    protected void onPause() { 
     super.onPause(); 
if(mMediaPlayer.isPlaying()) { 
    mMediaPlayer.release(); 
    mMediaPlayer.stop(); 
} 

    } 


    @Override 
    protected void onDestroy() { 
     super.onDestroy(); 
     if(mMediaPlayer.isPlaying()) { 
      mMediaPlayer.release(); 
      mMediaPlayer.stop(); 
     } 

    } 
}

類的軌道

public class Track { 

    public long  id;    
    public long  albumId;  
    public long  artistId;  
    public String path;   
    public String title;   
    public String album;   
    public String artist;  
    public Uri uri;   // URI 
    public long  duration;  
    public int  trackNo;  



    public static final String[] COLUMNS = { 
      MediaStore.Audio.Media._ID, 
      MediaStore.Audio.Media.DATA, 
      MediaStore.Audio.Media.TITLE, 
      MediaStore.Audio.Media.ALBUM, 
      MediaStore.Audio.Media.ARTIST, 
      MediaStore.Audio.Media.ALBUM_ID, 
      MediaStore.Audio.Media.ARTIST_ID, 
      MediaStore.Audio.Media.DURATION, 
      MediaStore.Audio.Media.TRACK, 
    }; 


    public Track(Cursor cursor) 
    { 
     id    = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media._ID)); 
     path   = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA)); 
     title   = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE)); 
     album   = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM)); 
     artist   = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST)); 
     albumId   = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID)); 
     artistId  = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST_ID)); 
     duration  = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION)); 
     trackNo   = cursor.getInt(cursor.getColumnIndex(MediaStore.Audio.Media.TRACK)); 
     uri    = ContentUris.withAppendedId(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, id); 
    } 



    public static List getItems(Context activity) { 

     List tracks = new ArrayList(); 
     ContentResolver resolver = activity.getContentResolver(); 
     Cursor cursor = resolver.query(
       MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, 
       Track.COLUMNS, 
       null, 
       null, 
       null 
     ); 
     while(cursor.moveToNext()){ 
      if(cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION)) < 3000){continue;} 
      tracks.add(new Track(cursor)); 
     } 
     cursor.close(); 
     return tracks; 
    } 



}

來源

2015-06-26 user3264924

也把你的Track類。 –

對不起，您的意思是顯示示例代碼？我已添加編輯 – user3264924

試試這個，

mMediaPlayer.setDataSource(MainActivity.this, contentUri);

更換

mMediaPlayer.setDataSource(tracks.get(position).path);

然後正常工作。

來源

2015-06-26 09:18:35

中的代碼是否正常工作？ –

如何從android中的Cursor播放歌曲？

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