如何将WriteableBitmap转换为BitmapImage？

Question

BitmapImage bitmapImage = new BitmapImage(new Uri("arka_projects_as_logo.png", UriKind.Relative));
Image uiElement = new Image() { Source = bitmapImage };
ScaleTransform t = new ScaleTransform() { ScaleX = 0.2, ScaleY = 0.2 };
WriteableBitmap writeableBitmap = new WriteableBitmap(uiElement,t);

我想将此转换的结果（writeableBitmap）插入到System.Windows.Controls.Image中。当我这样做时：

Image arkaImage = new Image() { Source = writeableBitmap };

arkaImage根本没有显示。有什么办法可以让它发挥作用？

Answer 1

WriteableBitmap wb = ..
using (MemoryStream ms = new MemoryStream())
{
    wb.SaveJpeg(ms, (int)image1.Width, (int)image1.Height, 0, 100);
    BitmapImage bmp = new BitmapImage();
    bmp.SetSource(ms);
}

Answer 2

为什么不将ScaleTransform同时应用于UIElement？