アルバムアートワーク/サムネイルを画像ビューに追加する

Question

私は初心者ですが、私は何をするべきかわかりません。各曲のアートワークをrecyclerviewに追加しようとしています。 "while {"の後に "albumCursor.moveToNext（）"という行を削除すると、すべての曲に同じ画像が追加されます。しかし、私がそれを残すと、アプリがクラッシュします。 私はそれが同じ名前を持っているすべてのサムネイルを引き起こすクラッシュだと思うが、私はそれを変更する方法を理解できません。

public void getSongList() { 
    //retrieve song info 
    ContentResolver musicResolver = getActivity() .getContentResolver(); 
    Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; 
    Uri albumUri = android.provider.MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI; 
    Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null); 
    Cursor albumCursor = musicResolver.query(albumUri, null, null, null, null); 
    songList = new ArrayList<Song>(); 



    if(musicCursor!=null && musicCursor.moveToFirst() 
      && albumCursor!=null && albumCursor.moveToFirst()){ 
     //get columns 
     int titleColumn = musicCursor.getColumnIndex 
       (MediaStore.Audio.Media.TITLE); 
     int idColumn = musicCursor.getColumnIndex 
       (MediaStore.Audio.Media._ID); 
     int artistColumn = musicCursor.getColumnIndex 
       (MediaStore.Audio.Media.ARTIST); 
     int durationColumn = musicCursor.getColumnIndex 
       (MediaStore.Audio.Media.DURATION); 
     int albumColumn = musicCursor.getColumnIndex 
       (MediaStore.Audio.Media.ALBUM); 
     int albumIdColumn = albumCursor.getColumnIndex 
       (MediaStore.Audio.Albums._ID); 
     int thumbColumn = albumCursor.getColumnIndex 
       (MediaStore.Audio.Albums.ALBUM_ART); 


     //add songs to list 
     do { 

      long thisAId = albumCursor.getLong(albumIdColumn); 
      String img = albumCursor.getString(thumbColumn); 
      File imgFile = new File (img); 
      Bitmap thisThumb = (ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(imgFile.getAbsolutePath()), 40, 40)); 

      long thisId = musicCursor.getLong(idColumn); 
      String thisTitle = musicCursor.getString(titleColumn); 
      String thisArtist = musicCursor.getString(artistColumn); 
      long thisDuration = musicCursor.getLong(durationColumn); 
      String thisAlbum = musicCursor.getString(albumColumn); 
      //Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath()); 
      //int thisThumb = albumCursor.getInt(thumbColumn); 


      songList.add(new Song(thisId, thisTitle, thisArtist, thisDuration, thisAlbum, thisThumb, thisAId)); 
     } 
     while (musicCursor.moveToNext() && albumCursor.moveToNext()); 
    } 

} 

私はあなたたちはただ聞いて、より多くの情報やコードが必要な場合、それは、すべての曲にアートワークを追加したいです。

12-11 20:59:45.723 6137-6137/com.reaper.frag E/AndroidRuntime: FATAL EXCEPTION: main 
                  Process: com.reaper.frag, PID: 6137 
                  java.lang.NullPointerException 
                   at java.io.File.<init>(File.java:262) 
                   at com.reaper.frag.Fragment1.getSongList(Fragment1.java:168) 
                   at com.reaper.frag.Fragment1.onCreateView(Fragment1.java:88) 
                   at android.support.v4.app.Fragment.performCreateView(Fragment.java:2261) 
                   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1419) 
                   at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1750) 
                   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1819) 
                   at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:797) 
                   at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2590) 
                   at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2377) 
                   at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2332) 
                   at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2209) 
                   at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:649) 
                   at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:145) 
                   at android.support.v4.view.ViewPager.populate(ViewPager.java:1238) 
                   at android.support.v4.view.ViewPager.populate(ViewPager.java:1086) 
                   at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1616) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 
                   at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) 
                   at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:719) 
                   at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:791) 
                   at android.view.View.measure(View.java:21040) 
                   at com.sothree.slidinguppanel.SlidingUpPanelLayout.onMeasure(SlidingUpPanelLayout.java:803) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:719) 
                   at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:791) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) 
                   at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 
                   at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) 
                   at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) 
                   at android.view.View.measure(View.java:21040) 
                   at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6460) 
                   at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 
                   at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) 
                   at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) 
                   at 

Answer 1

私はそれを:)固定。だから誰かが同じ問題を抱えているなら、私は下に私の解決策を掲載しました。 まだアプリがすべての写真を読み込むまでに時間がかかりますが、開始日です

public void getSongList() { 
    //retrieve song info 
    ContentResolver musicResolver = getContentResolver(); 
    Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; 
    Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null); 

    Bitmap thisThumb = null; 
    byte[] art; 

    songList = new ArrayList<Song>(); 
    if(musicCursor!=null && musicCursor.moveToFirst()){ 
     //get columns 
     int titleColumn = musicCursor.getColumnIndex 
       (android.provider.MediaStore.Audio.Media.TITLE); 
     int idColumn = musicCursor.getColumnIndex 
       (android.provider.MediaStore.Audio.Media._ID); 
     int artistColumn = musicCursor.getColumnIndex 
       (android.provider.MediaStore.Audio.Media.ARTIST); 
     int durationColumn = musicCursor.getColumnIndex 
       (android.provider.MediaStore.Audio.Media.DURATION); 
     int albumColumn = musicCursor.getColumnIndex 
       (android.provider.MediaStore.Audio.Media.ALBUM); 
     int columnIndex = musicCursor.getColumnIndexOrThrow 
       (MediaStore.Audio.Media.DATA); 

     //add songs to list 
     do { 

      String pathId = musicCursor.getString(columnIndex); 
      Log.d(this.getClass().getName(), "path id=" + pathId); 

      metaRetriver.setDataSource(pathId); 

      try { 
       art = metaRetriver.getEmbeddedPicture(); 
       BitmapFactory.Options opt = new BitmapFactory.Options(); 
       opt.inSampleSize = 2; 
       thisThumb = (BitmapFactory .decodeByteArray(art, 0, art.length,opt)); 

       //Bitmap thisAThumb = (ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(imgFile.getAbsolutePath()), 40, 40)); 
       System.out.println("art `" + thisThumb+"`"); 

      } catch (Exception e) { 
       //imgAlbumArt.setBackgroundColor(Color.GRAY); 
      } 
      long thisId = musicCursor.getLong(idColumn); 
      String thisTitle = musicCursor.getString(titleColumn); 
      String thisArtist = musicCursor.getString(artistColumn); 
      String thisDuration = musicCursor.getString(durationColumn); 
      String thisAlbum = musicCursor.getString(albumColumn); 
      songList.add(new Song(thisId, thisTitle, thisArtist, thisDuration, thisAlbum, thisThumb)); 
     } 
     while (musicCursor.moveToNext()); 
    } 
}