Hello. I would like to create a diagram in a separate thread and use SvgExporter to export it into SVG. For that purpose, I create a separate thread and call thread.SetApartmentState(ApartmentState.STA); on it. But I get the "The calling thread cannot access this object because a different thread owns it." exception like this:

System.TypeInitializationException: The type initializer for 'MindFusion.Diagramming.Wpf.Diagram' threw an exception.
 ---> System.TypeInitializationException: The type initializer for 'MindFusion.Diagramming.Wpf.GraphicsUnit' threw an exception.
 ---> System.InvalidOperationException: The calling thread cannot access this object because a different thread owns it.
   at System.Windows.Threading.Dispatcher.<VerifyAccess>g__ThrowVerifyAccess|7_0()
   at System.Windows.Application.get_MainWindow()
   at MindFusion.Utilities.()
   at MindFusion.Diagramming.Wpf.GraphicsUnit..cctor()
   --- End of inner exception stack trace ---
   at MindFusion.Diagramming.Wpf.Diagram..cctor()
   --- End of inner exception stack trace ---
   at MindFusion.Diagramming.Wpf.Diagram..ctor()
   at MindFusionStaTest.MainWindow.CreateDiagram() in D:\work\MindFusionStaTest\MainWindow.xaml.cs:line 38
   at MindFusionStaTest.MainWindow.<>c__DisplayClass2_0.<STAButton_OnClick>b__0() in D:\work\MindFusionStaTest\MainWindow.xaml.cs:line 28
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
 

I prepared the sample application (attached) that allows to reproduce the issue.

Could you please take a look, what I'm doing wrong? Maybe I should use another approach of creating MindFusion diagram in another thread. Thanks!

This build should work from STA thread -
https://mindfusion.eu/_beta/wpfdiag4.zip

You'll need to freeze the bitmap too before passing it to UI thread:

var thread = new Thread(() =>
{
	image = CreateDiagram();
	image.Freeze();
});
...
Image.Source = image;
 

Regards,
Slavcho
Mindfusion