Using .Net DLL in VC6

[ZawMinTun]

Hello everyone, Now I'm facing some problems trying to use .Net 4.0 DLLs in VC6. Just to share some background info, it started with a requirement I need to use a (.Net 4.0 third-party) grid in an old VC6 application. I browsed the internet and got the information about the interop and COM and so on. Finally I arrived to this point: I used Microsoft's Interop Form Library in VS-2010 and created a dll file wrapping the third-party grid. Then from VB6 I tried to use it in VB6. It's working. I tried to do the same in VC6, but failed, and I also don't know exactly how to do exactly the same as in VB6. So I created VB6 ActiveX Control wrapping this dll. I used this ActiveX Control in VB6 exe applicaiton. It's working too. Then I tried to use the ActiveX control from VC6. I can load the grid on to the UI (by clicking a button). However, the intrinsic functions of the third-party grid (such as sorting by double-click on the column-header, group by the colums drag and drop) are not working anymore. Even when I click on the grid, the application hangs up. The error is saying something related with ".Net-BroadcastEventWindow". Can you please help me? Any information or guess-and-advise will be useful and really thankful. Best regards, Zaw Min Tun

[David Knechtges]

If you can recompile the old VC6 code using VS2010 and its compiler, then you will have an easier time. In this case, you can then change it to a C++/CLI project and then use any .NET controls you wish. Basically, just open the old VC6 project in VS2010 and recompile. If that works, then change the project over to C++/CLI and you are in business. If you cannot recompile the VC6 project, but can directly load DLLs, then you could use C++/CLI to be a wrapper DLL around the .NET stuff and call it from the old C style code. Using COM and Interop the way you did is not easy as you found out. That is why you might consider the 2 suggestions above.

[ZawMinTun]

Thanks a lot, David. The first option is probably a bit discouraging (for the source files are quite a lot and a bit messy already through the ages), so I'll be trying the second. In fact, I've already tried wrapping in C# and calling from VC++, but still in vain. So I will try this in C++/CLI. For your advice and time, thanks a lot. Best regards, Zaw Min Tun