protected override Java.Lang.Object DoInBackground(params Java.Lang.Object[] native_parms)
{
data = (int)native_parms[0];
ImageView imageView;
if (imageViewReference.TryGetTarget(out imageView))
{
var bitmap = ImageCache.DecodeSampledBitmapFromResource(imageView.Resources, data, widthRequest, heightRequest);
if (cache != null)
{
cache.Add(data.ToString(), bitmap);
}
return(bitmap);
}
return(null);
}
private static void AddInBitmapOptions(BitmapFactory.Options options, ImageCache cache)
{
// inBitmap only works with mutable bitmaps, so force the decoder to
// return mutable bitmaps.
options.InMutable = true;
if (cache != null)
{
// Try to find a bitmap to use for inBitmap.
Bitmap inBitmap = cache.GetBitmapFromReusableSet(options);
if (inBitmap != null)
{
// If a suitable bitmap has been found, set it as the value of
// inBitmap.
options.InBitmap = inBitmap;
}
}
}
public static Bitmap DecodeSampledBitmapFromFile(string filename, int reqWidth, int reqHeight, ImageCache cache)
{
BitmapFactory.Options options = new BitmapFactory.Options();
options.InJustDecodeBounds = true;
BitmapFactory.DecodeFile(filename, options);
AddInBitmapOptions(options, cache);
options.InJustDecodeBounds = false;
return(BitmapFactory.DecodeFile(filename, options));
}
public BitmapWorkerTask(ImageView imageView, int widthRequest, int heightRequest, ImageCache cache = null)
{
imageViewReference = new WeakReference <ImageView>(imageView);
this.cache = cache;
this.widthRequest = widthRequest;
this.heightRequest = heightRequest;
}
