Android :: Populate Downloaded Image And Show In Thumbnail View?

I am developing an app in android, which basically visits a given url and downloads an image. Now i want to populate this downloaded image and show it in thumbnail view. I have tried out displaying the same from SD Card, but when i am doing the same for downloaded files, it doesn't seems to work.

public View getView(int position,View convertView,ViewGroup parent)
{
System.gc();
ImageView i = new ImageView(mContext.getApplicationContext());
if (convertView == null)
{
//imagecursor.moveToPosition(position);
//int id = imagecursor.getInt(image_column_index);
//i.setImageURI(Uri.withAppendedPath(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, ""+ id));
i.setImageBitmap(bitmap);
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
i.setLayoutParams(new GridView.LayoutParams(100, 100));
}
else
{
i = (ImageView) convertView;
}
return i;
}