error C2872: 'IDataObject' : ambiguous symbol

[UtmostCathode]

I've been having some trouble with this error for a few hours now. It's a hard question to ask, because there's nothing specific about it. The error itself is ambiguous.

All I know is that it has to do with the order I include windows.h or dinput.h, or how many times. To expand: I need to create a DirectInput object to play around with a USB mouse, thus I need to include dinput.h, however, when I do this it spits out the error. It also gives the error if I do *not* include dinput, but include windows.h a second time somewhere in my project.

I'm working in Microsoft Visual C++ .NET, Visual Studio .net professional 2003. I've basically just been working with Forms, and now I want to create a user joystick interface.

 

[timmay3141]

Odd...could you post the code that is causing the error? You aren't trying to create an object of an interface are you? Probably not, I wouldn't think you'd get this error if you were. Do a lookup of where IDataObject is defined perhaps and you will get more of a clue. Perhaps there is more than one definition of IDataObject but defined in different namespaces?

 

[UtmostCathode]

Oh yeah in my angry haste I neglected to include the actual error:

C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\ObjIdl.h(7408): error C2872: 'IDataObject' : ambiguous symbol

And,

------ Build started: Project: Test06, Configuration: Debug Win32 ------

Compiling...

Color.cpp

C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\ObjIdl.h(246) : warning C4935: assembly access specifier modified from 'public'

C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\ObjIdl.h(258) : warning C4935: assembly access specifier modified from 'public'

C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\ObjIdl.h(7408) : error C2872: 'IDataObject' : ambiguous symbol

could be 'C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\ObjIdl.h(246) : System::Windows::Forms::IDataObject IDataObject'

or 'Color.cpp(0) : System::Windows::Forms::IDataObject'

C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\ObjIdl.h(7422) : fatal error C1903: unable to recover from previous error(s); stopping compilation



Build log was saved at "file://c:\Documents and Settings\jhenders\My Documents\Visual Studio Projects\currentTest\Debug\BuildLog.htm"

Test06 - 2 error(s), 2 warning(s)



And I'm not messing around with an interface at all - that I know of anyways. I'm new to Windows programming, so my code is embarassingly inefficient, since my goal was just trying to get it to function.

 

[UtmostCathode]

Update. It seems like commenting out using namespace System, and System::Windows::Forms - and hardcoding those in where necessary for their members - fixed the problem. Oh well, hope this can help someone else in the future.