WPF 保存绘制结果到图形文件

1. protected void SavePhoto
   (string fileName)  
2. {  
3. DrawingVisual drawingVisual = 
   new DrawingVisual();  
4. DrawingContext drawingContext = 
   drawingVisual.RenderOpen();  
5. // 画矩形  
6. Rect rect = new Rect(new 
   Point(160, 100), new Size(320, 80));  
7. drawingContext.DrawRectangle
   (Brushes.LightBlue, (Pen)null, rect);  
8. // 画文字  
9. drawingContext.DrawText(  
10. new FormattedText("Hello, world",  
11. CultureInfo.GetCultureInfo("en-us"),  
12. FlowDirection.LeftToRight,  
13. new Typeface("Verdana"),  
14. 36, Brushes.Black),  
15. new Point(100, 60));  
16. drawingCon