Hi Everyone,

I have a .NET 2.0 set of classes that i've recently attempted to call from
an MFC application using regasm to generate and register a type library. I
didn't author my classes with the intention that they would be called from
an unmanaged application and i've run into a few problems.

Let's say for example that i have a Class A. I could see this class in the
MFC app, but i couldn't see any of it's public methods or properties. It
wasn't until I made Class A implement Interface A that I could see the
methods using the interface and the following code

IClassA clsA(__uuidof(ClassA));

But what if I want Class A to inherit from two interfaces. If I can indeed
only access my methods using the interface, do I have to create two
variables, one for each interface?

I'm seriously hoping i've got something wrong along the way

thanks,
Andrew

Hi Andrew,

If an object exposes multiple interfaces, you need a separate interface
variable to access each one. This allows clients to program to an interface
rather than implementation and affords decoupling. This is good practice in
general, so that when someday you need to replace ClassA with SomeOtherAClass
your clients only need to update the CoClass.

"Andrew Brook" wrote:

Thanks for your response,

I guess this just means I need to design my classes a little better with
this in mind, good job i'm still at the design stage of this!

thanks again,
Andrew

"Foz" <Foz (AT) discussions (DOT) microsoft.com> wrote