I have recently moved my MFC project into Visual Studio .NET. I'm still using MFC and the bulk of the project is unmanaged code, but I'm also now using ADO .NET, so I'm #using <mscorlib.dll> and have "Use Managed Extensions" set to "Yes" in the project properties.
I have been using CMemDC which encapsulates double-buffering to cut down on flicker; you can see it here:
It worked fine for me in the past. However, it is not working any more. It doesn't crash or anything, it just doesn't put anything onto the screen when it gets to the BitBlt call. I'm using CMemDC in a dozen different places in my project and it's the same everywhere. I haven't made any changes to the GUI and certainly not to the CMemDC class since I moved over to VS .NET so I'm at a loss to explain why it's not working any more. Does anyone know?