Inspecting an instance of a COM / Interop class properly in VS.Net's debugger?

Answer 1

I've used the immediate window to manually query the properties of the COM object. The downside is that I don't think you get intellisense so you have to know exactly what you want to inspect.

Answer 2

From .NET and COM: The Complete Interoperability Guide:

When an instance of a COM object is returned to you, via a method's return type or a by-reference parameter, and the CLR can't determine the type, you'll get the generic System.__ComObject type because COM objects are always passed/returned as interface pointers.

You might try changing the return type using Marshal.CreateWrapperOfType as in the example below:

MyType newObject = (MyType)Marshal.CreateWrapperOfType(oldObject, typeof(MyType))

Then you can look at newObject in your watch window and it should have the expected properties.

If the call fails, it will throw an InvalidCastException.