silverlight中将图片控件保存到文件

silverlight中的图片控件没有直接将图片内容保存到文件的方法，也不能直接读出图片内容，需要借助silverlight3.0新增的一个类WriteableBitmap来保存。代码如下：

public static void SaveAsPNG(Image img) { SaveFileDialog sfd = new SaveFileDialog() { DefaultExt = "png",Filter = "Png files (*.png)|*.png|All files (*.*)|*.*",FilterIndex = 1 }; if (sfd.ShowDialog() == true) { var bitmap = new WriteableBitmap((BitmapImage)img<a href="/tag/so/" target="_blank" class="keywords">.so</a>urce); EditableImage imageData = new EditableImage(bitmap.PixelWidth,bitmap.PixelHeight); try { for (int y = 0; y < bitmap.PixelHeight; ++y) { for (int x = 0; x < bitmap.PixelWidth; ++x) { int pixel = bitmap.Pixels[bitmap.PixelWidth * y + x]; imageData.SetPixel(x,y,(byte)((pixel >> 16) & 0xFF),(byte)((pixel >> 8) & 0xFF),(byte)(pixel & 0xFF),(byte)((pixel >> 24) & 0xFF) ); } } } catch (Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>.S<a href="/tag/ecurity/" target="_blank" class="keywords">ecurity</a>.S<a href="/tag/ecurity/" target="_blank" class="keywords">ecurity</a>Exception) { throw new Exception("Cannot print images from other domains"); } // Save it to <a href="/tag/dis/" target="_blank" class="keywords">dis</a>k Stream pngStream = imageData.GetStream(); byte[] binaryData = new Byte[pngStream.Length]; pngStream.Read(binaryData,(int)pngStream.Length); Stream stream = sfd.OpenFile(); stream.Write(binaryData,binaryData.Length); stream.Close(); }