缩略图正在后台线程中创建，但在初始化时不显示

Question

当我启动我的应用程序时，我有一个Asynctask启动，它会查找任何新视频并创建缩略图并将它们添加到数据库中。我稍后使用Universal Image Loader查找并将该位图设置为视图。我的问题是，当我第一次启动我的应用程序时，所有数据都被加载到数据库但没有显示在gridview中。我甚至不认为适配器被调用。但是，当我在加载所有数据后启动应用程序时，gridview会显示所有缩略图并且运行顺畅。

我想知道为什么会发生这种情况以及我可以采取哪些措施来解决这个问题。我的代码在

之下

的AsyncTask

private class DataEntry extends AsyncTask<Void, Integer, GridviewData>{
GridviewData dataentry;
DataEntry(GridviewData gridviewdata){
    this.dataentry = gridviewdata;

}

@Override
protected GridviewData doInBackground(Void... params) {

    cursor.moveToFirst();
    do {

        String videoid = cursor.getString(columnindexid);
        String videopath = cursor.getString(columnindexdata);

        int result = dataentry.findVideoID(videoid);
        if (result == 1){
            Bitmap bmthumb = ThumbnailUtils.createVideoThumbnail(videopath, MediaStore.Video.Thumbnails.MINI_KIND);
            if (bmthumb != null) {
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            bmthumb.compress(Bitmap.CompressFormat.JPEG, 100, stream);
            byte[] thumbnailBitmapBytes = stream.toByteArray();
            dataentry.addVideoinfo(videoid, videopath, thumbnailBitmapBytes);
            }
        }

        if (result == 0){
            Log.i(TAG, "Cursor wasn't processed, no getcount");
        }
        if(result == 2){
            //there is data already there
        }

    } while (cursor.moveToNext());
    Log.i(TAG, "After dowhile loop");
    cursor.close();

    return dataentry;

}

    }

基本图像加载器

public class SqliteImageDownloader extends BaseImageDownloader {

private static final String SCHEME_DB = "db";
private static final String DB_URI_PREFIX = SCHEME_DB + "://";
Cursor cursor;

public SqliteImageDownloader(Context context) {
    super(context);
}

@Override
protected InputStream getStreamFromOtherSource(String imageUri, Object extra) throws IOException {
    if (imageUri.startsWith(DB_URI_PREFIX)) {
        String path = imageUri.substring(19);
        cursor = entry.BitFinder(path); 
        byte[] imageData = cursor.getBlob(0);

        return new ByteArrayInputStream(imageData);
    } else {
        return super.getStreamFromOtherSource(imageUri, extra);
    }
}
}

光标适配器

class VideoAdapter extends CursorAdapter {
Cursor curs;
Context context; 
public VideoAdapter(Context context, Cursor c) {
    super(context, c);
    this.context = context;
    this.curs = c;

}

@Override
public void bindView(View view, Context context, Cursor cursor) {
    ViewHolder holder = (ViewHolder) view.getTag();
    String filepath = curs.getString(videopathindex);

    ImageLoader.getInstance().displayImage("db://VideoandThumbs" + filepath, holder.imageview);

}

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View eachgrid = inflater.inflate(R.layout.eachgrid, parent, false);
    ViewHolder holder = new ViewHolder();
    holder.imageview = (ImageView) eachgrid.findViewById(R.id.Imageview1);
    eachgrid.setTag(holder);
    return eachgrid;        
}

    }