Hi Peter,
Sorry for the delay in getting back to you.
We assume that your requirement is to serialize the Diagram into XAML, save into DataBase and then render the XAML as Image. We have created a simple sample to represent your requirement. Please refer to the sample from the attachment.
Sample details:
The buttons are used perform the save, Load and Export the diagram as Image respectively.
Please let us know if you have any concerns,
Regards,
Ramya
sample_1d5c6278.zip