Практическое руководство. Применение преобразования к объекту BitmapImage
В этом примере демонстрируется применение Transform для BitmapImage.
Пример
///// Create a BitmapImage and set it's DecodePixelWidth to 200. Use /////
///// this BitmapImage as a source for other BitmapSource objects. /////
BitmapImage myBitmapImage = new BitmapImage();
// BitmapSource objects like BitmapImage can only have their properties
// changed within a BeginInit/EndInit block.
myBitmapImage.BeginInit();
myBitmapImage.UriSource = new Uri(@"C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Water Lilies.jpg");
// To save significant application memory, set the DecodePixelWidth or
// DecodePixelHeight of the BitmapImage value of the image source to the desired
// height or width of the rendered image. If you don't do this, the application will
// cache the image as though it were rendered as its normal size rather then just
// the size that is displayed.
// Note: In order to preserve aspect ratio, set DecodePixelWidth
// or DecodePixelHeight but not both.
myBitmapImage.DecodePixelWidth = 200;
myBitmapImage.EndInit();
/////////////////// Create a BitmapSource that Rotates the image //////////////////////
// Use the BitmapImage created above as the source for a new BitmapSource object
// that will be scaled to a different size. Create a new BitmapSource by
// scaling the original one.
// Note: New BitmapSource does not cache. It is always pulled when required.
// Create the new BitmapSource that will be used to scale the size of the source.
TransformedBitmap myRotatedBitmapSource = new TransformedBitmap();
// BitmapSource objects like TransformedBitmap can only have their properties
// changed within a BeginInit/EndInit block.
myRotatedBitmapSource.BeginInit();
// Use the BitmapSource object defined above as the source for this BitmapSource.
// This creates a "chain" of BitmapSource objects which essentially inherit from each other.
myRotatedBitmapSource.Source = myBitmapImage;
// Flip the source 90 degrees.
myRotatedBitmapSource.Transform = new RotateTransform(90);
myRotatedBitmapSource.EndInit();