播放来自SDcard的MP3歌曲

Question

我正在从android中的sdcard访问歌曲，歌曲显示在ListView中，但我无法播放这些文件。

这里是代码：

package com.ex.imageGallery; 

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.database.Cursor; 
import android.media.AudioManager; 
import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.provider.MediaStore; 
import android.util.Log; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.BaseAdapter; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.media.MediaPlayer; 
import android.net.Uri; 

public class temp extends Activity{ 
     protected static final String TAG = null; 
    private Cursor audioCursor; 
     private int video_column_index; 
     private static String currentposition; 
     ListView videolist; 
     int count; 

     /** Called when the activity is first created. */ 
     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.list_audio); 
      //init_phone_video_grid(); 
      System.gc(); 
      final String[] proj = { MediaStore.Audio.Media._ID, 
    MediaStore.Audio.Media.DATA, 
    MediaStore.Audio.Media.DISPLAY_NAME, 
    MediaStore.Audio.Media.SIZE }; 

     audioCursor = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,proj, null, null, null); 
     count = audioCursor.getCount(); 
     videolist = (ListView) findViewById(R.id.PhoneVideoList); 
     videolist.setAdapter(new AudioAdapter(getApplicationContext())); 
     videolist.setOnItemClickListener(new OnItemClickListener() { 
      public void onItemClick(AdapterView<?> parent, View view, 
        int position, long id) { 
       //System.out.println(proj[0]); 
       System.out.println(audioCursor.getString(position)); 
       //Uri mur = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI+Uri.parse(audioCursor.getString(position)); 
       try{ 
       MediaPlayer mp = new MediaPlayer(); 
       mp.setDataSource(audioCursor.getString(position)); 
       mp.prepare(); 
       mp.start(); 
       } 
       catch(Exception ex) 
       { 
        System.out.println(ex); 
       } 


      } 



     }); 
    } 

    class AudioAdapter extends BaseAdapter { 
     private Context vContext; 

     public AudioAdapter(Context c) { 
      vContext = c; 
     } 

     public int getCount() { 
      return count; 
     } 

     public Object getItem(int position) { 
      return position; 
     } 

     public long getItemId(int position) { 
      return position; 
     } 

     public View getView(int position, View convertView, ViewGroup parent) { 
      System.gc(); 
      TextView tv = new TextView(vContext.getApplicationContext()); 
      String id = null; 
      if (convertView == null) { 
        video_column_index = audioCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME); 
        audioCursor.moveToPosition(position); 
        id = audioCursor.getString(video_column_index); 
        video_column_index = audioCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE); 
        audioCursor.moveToPosition(position); 
        id += "Size(KB):" + audioCursor.getString(video_column_index); 
        tv.setText(id); 
      } else 
        tv = (TextView) convertView; 
      return tv; 
     } 
} 

}

Answer 1

这也应该是有用的：http://knightswhocode.com/wordpress/2011/02/android-read-file-from-sdcard/

Answer 2

答案已经接受，但是这是你实际上在寻找：

http://androidsamples.blogspot.com/2009/06/displaying-list-of-music-files-stored.html

Answer 3

添加这个类代码...

public class SongsManager { 
    // SDCard Path 
    String MEDIA_PATH = new String(Environment.getExternalStorageDirectory().toString()); 

    private final ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>(); 

    public SongsManager() { 

    } 

    public SongsManager(String foldername) { 

     MEDIA_PATH = MEDIA_PATH + foldername +"/"; 
    } 

    /** 
    * Function to read all mp3 files from sdcard and store the details in 
    * ArrayList 
    * */ 
    public ArrayList<HashMap<String, String>> getPlayList() { 
     File home = new File(MEDIA_PATH); 

     if (home.listFiles(new FileExtensionFilter()).length > 0) { 
      for (File file : home.listFiles(new FileExtensionFilter())) { 
       HashMap<String, String> song = new HashMap<String, String>(); 
       song.put(
         "songTitle", 
         file.getName().substring(0, 
           (file.getName().length() - 4))); 
       song.put("songPath", file.getPath()); 

       // Adding each song to SongList 
       songsList.add(song); 
      } 
     } 
     // return songs list array 
     return songsList; 
    } 

    /** 
    * Class to filter files which are having .mp3 extension 
    * */ 
    class FileExtensionFilter implements FilenameFilter { 
     @Override 
     public boolean accept(File dir, String name) { 
      return (name.endsWith(".mp3") || name.endsWith(".MP3")); 
     } 
    } 
} 

创建这个类的一个instantce和阅读他们作为..

public ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>(); 


ArrayList<HashMap<String, String>> songsListData = new ArrayList<HashMap<String, String>>(); 

     SongsManager plm = new SongsManager(); 
     // get all songs from sdcard 
     this.songsList = plm.getPlayList(); 

     // looping through playlist 
     for (int i = 0; i < songsList.size(); i++) { 
      // creating new HashMap 
      HashMap<String, String> song = songsList.get(i); 

      // adding HashList to ArrayList 
      songsListData.add(song); 
     } 

播放这样的歌......

public void playSong(int songIndex){ 
     // Play song 
     try { 
      mp.reset(); 
      mp.setDataSource(songsList.get(songIndex).get("songPath")); 
      mp.prepare(); 
      mp.start(); 
      // Displaying Song title 
      String songTitle = songsList.get(songIndex).get("songTitle"); 
      songTitleLabel.setText(songTitle); 

      // Changing Button Image to pause image 
      btnPlay.setImageResource(R.drawable.btn_pause); 

      // set Progress bar values 
      songProgressBar.setProgress(0); 
      songProgressBar.setMax(100); 

      // Updating progress bar 
      updateProgressBar(); 
     } catch (IllegalArgumentException e) { 
      e.printStackTrace(); 
     } catch (IllegalStateException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    }