What does the IDockableWindow.UserData Property actually return?

Discussion created by Hornbydd Champion on Jun 3, 2014
Latest reply on Jun 9, 2014 by Hornbydd
ESRI/ArcObject Gurus.

I have developed a dockable window as an AddIn using VB .Net. When you use the Wizard to create the AddIn it creates a UserControl which one populates with drop downs, text boxes etc. This all works fine.

I have created a COM object so this compiles to a separate DLL which is referenced by MS Access. This COM object starts an instance of ArcMap and needs to pass a value from an Access form to a textbox on the Dockable Window. I can get a handle on the window using the IDockableWindowManager.GetDockableWindow Method but I can't figure out how to drill down to the Textbox. Presumably its via the UserData property? If I get the object returned by this property and run it through TypeName function it simply says its IUnknown.

Various threads on the forum and searches point to this blog. But this method requires you to be able to access the AddIn so you are running code within the ArcMap framework. The Addin is a file only understood by ArcMap and not something that MS Access can reference.

So my question is what is the object returned by UserData property, the help page on this topic is decidedly unhelpful?

Has anyone worked out how to cast what ever it returns into a usercontrol where you can drill down to the various controls on it?

I very much look forward to any advice on this as I have hit the "wall".