Hi and welcome

You could save the subform's diagram as a string using the SaveToString method, and assign the string to the master node's Tag or Id property, or any custom property you add to a derived node class. Upon double click, open the subform and call LoadFromString to load the previously saved diagram.

Another possibility is to save the diagrams into separate files, and keep file names as masternode.Tag values. You could use a Zip library such as icsharpcode.sharpziplib to store the diagrams in a single archive file.

Yet another one is to use a DiagramDocument, where the first page is your main diagram, next pages are sub-diagrams, and keep only page indices as master nodes' Tags.

I hope that helps,
Stoyan

Hi,

You could add a "public DiagramNode MasterNode" property to your sub-diagram form. Assign subForm.MasterNode = e.Node before showing the form from NodeDoubleClicked, and set MasterNode.Tag when closing the form.

I hope that helps,
Stoyan

Hi Stoyo,
  One more query in this:
If I am saving the subform diagram in ASCII format, does it mean that for whatever nodes are there in the subform, I won't be able to track/set their id's in the saved xml?

Thanks a lot Stoyan.