HOW TO：對 BitmapImage 套用轉換
更新：2007 年 11 月
本範例示範如何將 Transform 套用到 BitmapImage。
範例
'/// 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()
///// 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();