public object GetImageFromUri(FileUri imageUri, int targetWidth, int targetHeight, int rotation)
{
using (Stream stream = GetFileSystem().OpenFile(imageUri, UniversalFileMode.Open, UniversalFileAccess.Read, UniversalFileShare.Read))
{
CGImageSource source = CGImageSource.FromUrl(imageUri.ToNSUrl());
CGImageOptions options = new CGImageOptions();
options.ShouldCache = false;
var props = source.CopyProperties(options, 0);
int imageWidth = ((NSNumber)props["PixelWidth"]).Int32Value;
int imageHeight = ((NSNumber)props["PixelHeight"]).Int32Value;
int scale = 1;
while (imageWidth / scale / 2 >= (nfloat)targetWidth &&
imageHeight / scale / 2 >= (nfloat)targetHeight)
{
scale *= 2;
}
stream.Seek(0, SeekOrigin.Begin);
UIImage image = UIImage.LoadFromData(NSData.FromUrl(imageUri.ToNSUrl()), scale);
if (rotation != 0)
{
float radians = rotation * (float)Math.PI / 180f;
CGRect imageFrame = new CGRect(0, 0, image.Size.Width, image.Size.Height);
CGAffineTransform t = CGAffineTransform.MakeRotation(radians);
imageFrame = t.TransformRect(imageFrame);
CGSize rotatedSize = new CGSize(imageFrame.Width, imageFrame.Height);
UIGraphics.BeginImageContext(rotatedSize);
using (CGContext context = UIGraphics.GetCurrentContext())
{
context.TranslateCTM(rotatedSize.Width / 2, rotatedSize.Height / 2);
context.RotateCTM(-radians);
context.ScaleCTM(1.0f, -1.0f);
image.Draw(new CGRect(-image.Size.Width / 2, -image.Size.Height / 2, image.Size.Width, image.Size.Height));
image = UIGraphics.GetImageFromCurrentImageContext();
}
UIGraphics.EndImageContext();
}
return(image);
}
}
