Cannot Convert Inventor._Document to Inventor.AssemblyDocument

[shiftctrl.io]

Hi All,

As I'm learning C#, I thought I'd play with converting some of my VB.NET stuff over to C# as practice. I'm getting jammed up pretty quick here, as I can't figure why I'm getting this error:

Cannot Convert Inventor._Document to Inventor.AssemblyDocument

If I declare it as a Document instead of an AssemblyDocument, then I can't access the AssemblyComponentDefinition interface. 

If I cast the ActiveDocument then the error goes away, but I get another message of a suspicious cast. 

How do you normally going about getting the Active (assembly) Document via C#?

[shiftctrl.io · Accepted solution]

Well, not sure what is going on with that suspicious cast alert, regardless - it works just fine as long as you cast the _Document to an AssemblyDocument.