从位于网址的位图获取缩略图

Question

在Xamarin中，是否可以获取托管在网址上的Bitmap缩略图？

我有这段代码：

public static int CalculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
{
    // Raw height and width of image
    var height = (float)options.OutHeight;
    var width = (float)options.OutWidth;
    var inSampleSize = 1D;

    if (height > reqHeight || width > reqWidth)
    {
        inSampleSize = width > height
                            ? height/reqHeight
                            : width/reqWidth;
    }

    return (int) inSampleSize;
}

public static Bitmap DecodeSampledBitmapFromResource(Resources res, int resId, int reqWidth, int reqHeight)
{
    // First decode with inJustDecodeBounds=true to check dimensions
    var options = new BitmapFactory.Options {
        InJustDecodeBounds = true,
    };
    using (var dispose = BitmapFactory.DecodeResource(res, resId, options)) {
    }

    // Calculate inSampleSize
    options.InSampleSize = CalculateInSampleSize(options, reqWidth, reqHeight);

    // Decode bitmap with inSampleSize set
    options.InJustDecodeBounds = false;
    return BitmapFactory.DecodeResource(res, resId, options);
}

是否可以修改此代码以获取存储在网址中的Bitmap缩略图？

提前致谢