UIViewの外観を画像として取得する

MonoTouchのView再構築時間が結構かかりストレスなので，終了直前の画像を表示して置こうと考えました．Viewの画像取得は次のコードでできます．_targetViewおよび_copyViewはそれぞれUIView，UIImageViewクラスです．

 {
            /*
             * http://www.iphonedevsdk.com/forum/iphone-sdk-development/2592-how-copy-image-uiview-another-uiview.html
             * 
             * UIGraphicsBeginImageContext(self.bounds.size);
             * [self.layer renderInContext:UIGraphicsGetCurrentContext()];
             * UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
             * UIGraphicsEndImageContext();             
             
             * I'm loading in an image into an UIImageView 
             * "[imageView.layer renderInContext:UIGraphicsGetCurrentContext()];".             
             * The UIImageView takes care of scaling and cropping the image. Then I get viewImage from that UIImageView.
             * */

            UIGraphics.BeginImageContext(_targetView.Bounds.Size);
            _targetView.Layer.RenderInContext(UIGraphics.GetCurrentContext());
            var img = UIGraphics.GetImageFromCurrentImageContext();
            UIGraphics.EndImageContext();

            _copyView.Image = img;            
        }