Question

I have a third party app that is a C# dll and I am trying to make calls to it from a plain C code. I have been able to create a C++ executable and call a C# dll with info I found here. But I’m looking for a plain C, has anyone done this before?

Answer 1

COM works just fine in plain C. Your example should work almost exactly like it is, however you will have to use C syntax for calling a function associated with an object. Change

pICalc->Add(5, 10, &lResult);

to

pICalc->lpVtbl->Add(pICalc, 5, 10, &lResult); // no implicit this pointer, pass explicitly

For more examples, see http://www.codeproject.com/Articles/13601/COM-in-plain-C#C