title: Writing a C++ DLL, then wrapping it in C#
body: <p>I am a bit confused about wrapping a c++ dll in c#.
  What kind of dll should i create? A normal dll or an mfc dll? Should i prefix every proto with "extern..." ? Should i write the functions in a def file?</p>
  
  <p>My last effort was in vain, c# would crash with an error like "bad image format", which means that the dll format is not correct?</p>
  
  <p>Any help would be much appreciated.</p>
  
  <p>Thanks in advance :-)</p>