更改曲目媒體播放器android

Question

我目前正在播放一首使用MediaPlayer播放音樂的歌曲。在用戶選擇一首不同的歌曲時，我試圖播放它。 但是，MediaPlayer出現錯誤（1，-2147483648）和Error（1，-2147483648）。 在調用prepareASync（）之後打印這些日誌。 注意：文件的路徑看起來是正確的。但是，如何檢查有效的文件路徑？

的順序如下：

  mPlayer.reset(); 
      Log.d(TAG,"after reset"); 
      mPlayer.setDataSource(mTrackToBePlayed); 
      Log.d(TAG,"after setDataSource"); 
      // mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); 
      mPlayer.setOnPreparedListener(preparedListener); 
      Log.d(TAG,"after setOnPreparedListener"); 
      mPlayer.setOnErrorListener(errorListener); 
      Log.d(TAG,"after setting errorListener"); 
      mPlayer.prepareAsync(); 
      Log.d(TAG,"after prepareAsync"); 

參考的代碼是這樣的：在我的主要活動的onResume（）（上回我要開始播放它，）我正在調用MusicUtils。的createPlayer（）;和 MusicUtils.playTrack（mCurrentTrack）;

public static void playTrack(String track) { 

    mTrackToBePlayed = track; 

    try { 
      mPlayer.reset(); 
      Log.d(TAG,"after reset"); 
      mPlayer.setDataSource(mTrackToBePlayed); 
      Log.d(TAG,"after setDataSource"); 
      // mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); 
      mPlayer.setOnPreparedListener(preparedListener); 
      Log.d(TAG,"after setOnPreparedListener"); 
      mPlayer.setOnErrorListener(errorListener); 
      Log.d(TAG,"after setting errorListener"); 
      mPlayer.prepareAsync(); 
      Log.d(TAG,"after prepareAsync"); 

    } catch (IOException e) { 

    } catch(IllegalArgumentException e) { 

    } 

    preparedListener = new MediaPlayer.OnPreparedListener() { 

     @Override 
     public void onPrepared(MediaPlayer mp) { 
      // TODO Auto-generated method stub 
      mp.start(); 
      Log.d(TAG,"after start"); 
     } 
    }; 

    errorListener = new MediaPlayer.OnErrorListener() { 
     public boolean onError(MediaPlayer mp, int what, int extra) { 
      switch (what) { 
      case MediaPlayer.MEDIA_ERROR_SERVER_DIED: 
       Log.d(TAG,"in onError"); 
       // mIsInitialized = false; 
       mp.release(); 
       // Creating a new MediaPlayer and settings its wakemode does not 
       // require the media service, so it's OK to do this now, while the 
       // service is still being restarted 
       try{ 
       mp = new MediaPlayer(); 
       mp.reset(); 
       mp.setDataSource(mTrackToBePlayed); 
       // mp.setAudioStreamType(AudioManager.STREAM_MUSIC); 
       mp.prepareAsync(); 
       mPlayer = mp; 
       // mPlayer.start(); 
       } catch (Exception e) { 

       } 
       //MediaPlayer.create(mContext, mTrackToBePlayed); 
       // mPlayer.setWakeMode(MediaPlaybackService.this, PowerManager.PARTIAL_WAKE_LOCK);     
       return true; 
      default: 
       Log.d("MusicPlayer", "Error: " + what + "," + extra); 
       break; 
      } 
      return false; 
     } 
    }; 


    //mPlayer.start(); 

} 

public static boolean isPlaying() { 
    return mPlayer.isPlaying(); 
} 

public static void pauseTrack() { 
    mPlayer.pause(); 
} 

public static void startTrack() { 
    mPlayer.start(); 
} 

public static void stopTrack() { 
    mPlayer.stop(); 
} 

public static void releasePlayer() { 
    mPlayer.release(); 
} 

This function is present in MusicUtils and is used to obtain the first track that the cursor returns

public static void retrieveDefaultPath() { 

    String[] STAR = { "*" };   
    Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;  
    String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";  
    mCursor = mContentResolver.query(allsongsuri, STAR, selection, null, null);  
    if (mCursor != null) {   
     if (mCursor.moveToFirst()) {   
      //do {    
       //mSongName = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME)); 
       //mSongList.add(mSongName);//populate the list of display names 
       int song_id = mCursor.getInt(mCursor.getColumnIndex(MediaStore.Audio.Media._ID)); 
       //mMusicIDs.put(song_id, counter++);//fill the HashMap with IDs corresponding to the positions 
       String fullpath = mCursor.getString(mCursor.getColumnIndex(MediaStore.Audio.Media.DATA));    
       String album_name = mCursor.getString(mCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM));   
       int album_id = mCursor.getInt(mCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));    
       String artist_name = mCursor.getString(mCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));   
       int artist_id = mCursor.getInt(mCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST_ID));   
       //} while (cursor.moveToNext());  


       mDefaultPath = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI + "/" + song_id; 
       Slideshow.mCurrentTrack = mDefaultPath; 

    }  
     if (mCursor != null) { 
      mCursor.close(); 
     } 
    } 
} 

The following function is used to obtain all the tracks on the device to display using the ListActivity.

public void getAllSongsFromSDCARD() {  
    String[] STAR = { "*" };   
    Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;  
    String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";  
    cursor = managedQuery(allsongsuri, STAR, selection, null, null);  
    if (cursor != null) {   
     if (cursor.moveToFirst()) {   
      do {    
       mSongName = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME)); 
       mSongList.add(mSongName);//populate the list of display names 
       int song_id = cursor.getInt(cursor.getColumnIndex(MediaStore.Audio.Media._ID)); 
       Log.d("Music List","ID: "+song_id+" counter:"+counter); 

       mMusicIDs.put(counter++, song_id);//fill the HashMap with IDs corresponding to the positions 
       String fullpath = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));    
       String album_name = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM));   
       int album_id = cursor.getInt(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));    
       String artist_name = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));   
       int artist_id = cursor.getInt(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST_ID));   
       } while (cursor.moveToNext());  
    }  
     cursor.close();  
    } 
} 

I use the ID that the user selects and obtain the filepath in the following way:

music_id = (Integer)mMusicIDs.get(position); 
mSelectedPath = mSelectedPath + "/" + music_id; 

logcat的：

08-31 18：07：36.348：d/dalvikvm（23090）：GC_EXTERNAL_ALLOC釋放2K，46％的遊離3088K/5703K，外部1461K/1538K，暫停爲32ms

08-31 18：07：38.860：d /標籤（23090）：內部的OnCreate

08-31 18：07：38.860：d/ImageSwitcher（23090）：高速緩存的大小：1

08-31 18：07：39.030：d/ImageSwitcher（23090）：TOTAL NUM IMAGES：838

08-31 18：07：39.150：I/AudioSystem（23090）：越來越音頻拋油

08-31 18：07：39.150：I/AudioSystem（23090）：返回新的音頻會話ID

08 -31 18：07：39.150：D/IAudioFlinger（23090）：newAudioSessionId

08-31 18：07：39.150：D/IAudioFlinger 23090）：newAudioSessionId缺貨，ID = 175

08-31 18：07：39.150：d/MediaPlayer的（23090）：07：39.150：在

08-31 18復位（）d/MediaPlayer的（ 23090）：復位（）出

08-31 18：07：39.150：d/MusicUtils（23090）：復位後

08-31 18：07：39.160：d/MusicUtils（23090）：後setDataSource

08-31 18：07：39.160：D/MusicUtils（23090）：setOnPreparedListener之後

08-31 18：07：39.160：d/MusicUtils（23090）：之後設置errorListener

08-31 18：07：39.170：d/MusicUtils（23090）：後prepareAsync

08- 31 18：07：39.250：d/MediaPlayer的（23090）：開始（）在

08-31 18：07：39.260：d/MediaPlayer的（23090）：開始（）出

08-31 18 ：07：39。270：d/MediaPlayer的（23090）：開始（）在

08-31 18：07：39.270：d/MediaPlayer的（23090）：開始（）出

08-31 18：07：39.270： d/MusicUtils（23090）：啓動後

08-31 18：07：49.340：d/MediaPlayer的（23090）：暫停（）在

08-31 18：07：49.340：d/MediaPlayer的（ 23090）：暫停（）out 08-31 18：07：49.560：D/dalvikvm（23090）：GC_CONCURRENT已釋放239K，45％空閒3260K/5831K，外部494K/1006K，暫停10ms + 7ms

08-31 18：07：50.842：d /音樂列表（23090）：在的onCreate getAllSongsFromSDCARD

前

08-31 18：07：50.922：d/TAG（23090）：設置適配器

08- 31 18：07：50.922：D/TAG（23090）：設置適配器完成

08-31 18：07：51.953：D/dalvikvm（23090）：GC_EXTERNAL_ALLOC釋放146K，45％空閒3264K/5831K，外部794K/855K，暫停29ms

08-31 18：07：53.905：d/MusicList（23090）：setItemChecked後

08-31 18： 07：54.585：d /設置（23090）：內onActivityResult

08-31 18：07：55.476：W/KeyCharacterMap（23090）：無法打開keycharmap文件

08-31 18:07： 55.476：W/KeyCharacterMap（23090）：Error loading loading keycharmap

file'/system/usr/keychars/cy8c-touchscreen.kcm.bin'。 hw.keyboards.65538.devname = 'cy8c-觸摸屏' 08-31 18：07：55.476：I/KeyCharacterMap（23090）：使用默認 鍵盤佈局/system/usr/keychars/qwerty.kcm.bin

08-31 18：07：55.486：d/MediaPlayer的（23090）：復位（）在

08-31 18：07：55.486：d/MediaPlayer的（23090）：復位（）出

08 -31 18：07：55.486：d/MusicUtils（23090）：復位

08-31 18後：07：55.486：d/MusicUtils（23090）：的setDataSource後

08-31 18：07：55.486：d/MusicUtils（23090）：後setOnPreparedListener

08-31 18：07：55.486：d/MusicUtils（23090）：在設置errorListener

08-31後18：07：55.486：d/MusicUtils（23090）：07：55.496：prepareAsync

08-31 18後E/MediaPlayer的（23090）：錯誤（1，-2147483648）

08-31 18 ：07：55.506：E/MediaPlayer（23090）：錯誤（1，-2147483648）

08-31 18：07：55.506 ：D/MusicPlayer（23090）：錯誤：1，-2147483648

Answer 1

該序列是正確的。路徑出錯了。正在使用硬編碼的字符串而不是Uri。謝謝。

Answer 2

**Check with the following class it will list out all th songs in the device also it play the song when click on that name.** 



public class NewMp3PlayerActivity extends Activity { 
     ListView musiclist; 

     int music_column_index,music_column_index1; 
     int count; 
     MediaPlayer mMediaPlayer; 
     ImageView play, pause, forward, backward; 
     int pposition; 
     ArrayList<String> songs = new ArrayList<String>();  String songName; Cursor musiccursor; 
     /** Called when the activity is first created. */ 
     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.songpreview); 

      play = (ImageView)findViewById(R.id.img_play); 
      pause = (ImageView)findViewById(R.id.img_pause); 
      forward = (ImageView)findViewById(R.id.img_forward); 
      backward = (ImageView)findViewById(R.id.img_backward); 

      play.setOnClickListener(OnClick); 
      pause.setOnClickListener(OnClick); 
      forward.setOnClickListener(OnClick); 
      backward.setOnClickListener(OnClick); 
      init_phone_music_grid(); 


     } 

     View.OnClickListener OnClick = new View.OnClickListener() { 
       @Override  public void onClick(View v) {   music_column_index = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);   

      Log.e("", "musiccursor.getCount()-->"musiccursor.getCount());   switch(v.getId()){   case R.id.img_play: 
       Log.v("", "list of songs-->"+songs); 
        if (mMediaPlayer.isPlaying()) { 
         mMediaPlayer.reset(); 
       } 
        mMediaPlayer.start(); 
       break;   case R.id.img_pause: 
        if (mMediaPlayer.isPlaying()) { 
         mMediaPlayer.pause(); 
       } 
       break;   case R.id.img_forward: //    musiccursor.moveToPosition(pposition+1); 

       try { 
        String filename=""; 
         if (pposition < songs.size()){ 
          pposition = pposition+1; 
          filename = songs.get(pposition);//musiccursor.getString(music_column_index); 
         }else{ 

         } 

         Log.e("", "filename-->"+filename); 
        mMediaPlayer.reset(); 
        mMediaPlayer.setDataSource(filename); 
        mMediaPlayer.prepare(); 
        mMediaPlayer.start(); 
       } catch (IllegalArgumentException e) { 
        e.printStackTrace(); 
       } catch (IllegalStateException e) { 
        e.printStackTrace(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } catch(IndexOutOfBoundsException ie){ 
        pposition = 0; 
       } 

       break;   case R.id.img_backward: 

       try { 
        String filename_n=""; 
         if (pposition <= songs.size()){ 
          pposition = pposition-1; 
          filename_n = songs.get(pposition);//musiccursor.getString(music_column_index); 
         }else{ 

         } 
         mMediaPlayer.reset(); 
         mMediaPlayer.setDataSource(filename_n); 
         mMediaPlayer.prepare(); 
         mMediaPlayer.start(); 
        } catch (IllegalArgumentException e) { 
         // TODO Auto-generated catch block 
         e.printStackTrace(); 
        } catch (IllegalStateException e) { 
         e.printStackTrace(); 
        } catch (IOException e) { 
         e.printStackTrace(); 
        } catch(ArrayIndexOutOfBoundsException ar){ 
         pposition = songs.size(); 
        } 
       break;   default: 
       break;   } 
        } }; 
     private void init_phone_music_grid() { 
      System.gc(); 
      String[] proj = { MediaStore.Audio.Media._ID,MediaStore.Audio.Media.DATA,MediaStore.Audio.Media.DISPLAY_NAME,MediaStore.Video.Media.SIZE }; 
      musiccursor = managedQuery(MediaStore.Audio.Media.INTERNAL_CONTENT_URI, proj, null, null, null); 
      Log.e("", "filename-->"musiccursor.getCount()); 
      count = musiccursor.getCount(); 
      musiclist = (ListView) findViewById(R.id.lst_music); 
      musiclist.setAdapter(new MusicAdapter(getApplicationContext())); 

      musiclist.setOnItemClickListener(musicgridlistener); 
      mMediaPlayer = new MediaPlayer(); 
      mMediaPlayer.setOnCompletionListener(new OnCompletionListener() { 

       @Override 
       public void onCompletion(MediaPlayer mp) { 
        try { 
         String filename=""; 
          if (pposition < songs.size()){ 
           pposition = pposition+1; 
           filename = songs.get(pposition);//musiccursor.getString(music_column_index); 
          }else{ 

          } 

          Log.e("", "filename-->"+filename); 
         mMediaPlayer.reset(); 
         mMediaPlayer.setDataSource(filename); 
         mMediaPlayer.prepare(); 
         mMediaPlayer.start(); 
        } catch (IllegalArgumentException e) { 
         e.printStackTrace(); 
        } catch (IllegalStateException e) { 
         e.printStackTrace(); 
        } catch (IOException e) { 
         e.printStackTrace(); 
        } catch(IndexOutOfBoundsException ie){ 
         pposition = 0; 
        } 
       }   }); 
     } 

     private OnItemClickListener musicgridlistener = new OnItemClickListener() { 
      public void onItemClick(AdapterView parent, View v, int position,long id) { 
        System.gc(); 
        pposition = position; 
        music_column_index = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA); 
        musiccursor.moveToPosition(position); 
        String filename = musiccursor.getString(music_column_index); 
        String filen = songs.get(pposition); 
        Log.e("", "index-->"+music_column_index); 
        try { 
         mMediaPlayer.reset(); 
         mMediaPlayer.setDataSource(filen); 
         mMediaPlayer.prepare(); //      mMediaPlayer.start(); 
        } catch (Exception e) { 

        } 
      } 
     }; 



     public class MusicAdapter extends BaseAdapter { 
      private Context mContext; 

      public MusicAdapter(Context c) { 
        mContext = 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(mContext.getApplicationContext()); 
        String id = null; 
        if (convertView == null) {      
         music_column_index = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME); 
         music_column_index1 = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA); 
         musiccursor.moveToPosition(position); 
         id = musiccursor.getString(music_column_index); 
         songName = musiccursor.getString(music_column_index); 
         songs.add(musiccursor.getString(music_column_index1)); 
         music_column_index = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE); 
         musiccursor.moveToPosition(position); 
         id += " Size(KB):" + musiccursor.getString(music_column_index); 
         tv.setText(id); 
        } else 
         tv = (TextView) convertView; 
        return tv; 
      } 
     } }