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How to: Apply a Transform to a BitmapImage

This example demonstrates how to apply a Transform to a BitmapImage.


'/// Create a BitmapImage and set it's DecodePixelWidth to 200. Use  /////
'/// this BitmapImage as a source for other BitmapSource objects.    /////
Dim myBitmapImage As 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.
Dim myRotatedBitmapSource As 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()


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