如何將WriteableBitmap轉換爲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); 

我想將此轉換的結果（writeableBitmap）插入到System.Windows.Controls.Image中。當我這樣做：

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

arkaImage根本沒有顯示。可以做些什麼來使其發揮作用？

Answer 1

爲什麼你不只是將ScaleTransform應用於UIElement？

Answer 2

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); 
}