获取AlbumArt时出现内存不足异常

Question

在这里，我创建了可扩展的列表视图，该列表具有Artist的组行，并且在子级中显示了具有专辑封面的Artist的所有专辑。 但是它抛出了内存不足的异常。

这是我获取图像的代码：

public static Bitmap getArtwork(Context context, int album_id) {

        ContentResolver res = context.getContentResolver();
        Uri uri = ContentUris.withAppendedId(sArtworkUri, album_id);
        if (uri != null)
        {
            InputStream in = null;
            try 
            {
                in = res.openInputStream(uri);
                return BitmapFactory.decodeStream(in, null, sBitmapOptions);
            } catch (FileNotFoundException ex) 
            {
                // The album art thumbnail does not actually exist. Maybe the user deleted it, or
                // maybe it never existed to begin with.
            } finally
            {
                    if (in != null)
                    {
                        try
                        {
                            in.close();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }
             }
        return null;
    }

对于创建子相册列表，我这样做：

private ArrayList<ArrayList<HashMap<String, Object>>> createChildList() {
    for (int i = 0; i < songsListData.size(); i++) 
    {

        ArrayList<HashMap<String,Object>> secList = new ArrayList<HashMap<String,Object>>();
        String s[] = new String[]{songsListData.get(i).get("artistname")};
        String whereClause = MediaStore.Audio.Albums.ARTIST + " = ? ";

        Cursor cursor = managedQuery(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI,null ,whereClause,s,null);

        if (cursor == null) 
        {
              //Query Failed , Handle error.
        }
        else if (!cursor.moveToFirst()) 
        {
             //No media on the device.
        }
        else
        {            
              int albumName = cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM);
              int id = cursor.getColumnIndex(MediaStore.Audio.Albums._ID);
              int songcount = cursor.getColumnIndex(MediaStore.Audio.Albums.NUMBER_OF_SONGS);

              for(int j=0;j<cursor.getCount();j++)
              {
                    String Name = cursor.getString(albumName);
                    Integer albumid = cursor.getInt(id);                        
                    Bitmap bitmap = null;
                    bitmap = getArtwork(context, albumid); //calling function
                    if(bitmap == null)
                    {
                        bitmap = BitmapFactory.decodeResource(context.getResources(),R.drawable.wallpaper);
                    }   
                    HashMap<String, Object> album = new HashMap<String, Object>();
                    album.put("albumName",Name);
                    album.put("albumId", albumid);  
                    album.put("image", bitmap);  //storing image
                    album.put("songcount",cursor.getString(songcount) + " song");
                    secList.add(album);
                    cursor.moveToNext();
               }                  
           }
           cursor.close();   
           albumData.add(secList);
    }
    return albumData;
}

我应该怎么处理内存不足异常？ 请给我一些解决方案。 谢谢

Answer 1

调试代码并跟踪堆大小是否意外增加（这一定是由于图像大小增加所致），您可以使用Document来了解Android如何计算图像大小

public static Bitmap getResizedBitmap(Bitmap image, int newHeight, int newWidth) {
    int width = image.getWidth();
    int height = image.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // create a matrix for the manipulation
    Matrix matrix = new Matrix();
    // resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);
    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(image, 0, 0, width, height,
            matrix, false);
    return resizedBitmap;
}