避免system.threading.threadabortexception错误(Avoid system.threading.threadabortexception error)

 好的，我已经在heltonbiker和Clemens的帮助下解决了这个问题。 
 
var size = new Size(794, 122);
Document.Measure(size);
Document.Arrange(new Rect(size));

Document.UpdateLayout();

RenderTargetBitmap rtb = new RenderTargetBitmap(794, 1122, 96d, 96d, System.Windows.Media.PixelFormats.Default);
rtb.Render(Document);
 
 但是当我将画布保存到光盘时，它的背景为黑色。 我通过在Canvas中的XAML中添加一个Rectangle来解决这个问题。 

Okay, I've got it fixed with the help of heltonbiker & Clemens.
 
var size = new Size(794, 122);
Document.Measure(size);
Document.Arrange(new Rect(size));

Document.UpdateLayout();

RenderTargetBitmap rtb = new RenderTargetBitmap(794, 1122, 96d, 96d, System.Windows.Media.PixelFormats.Default);
rtb.Render(Document);
 
But when I save my canvas to disc it had a black background. I solved this by adding a Rectangle to my XAML inside the Canvas.