title: Can I mix Qt and non-Qt projects in Visual Studio 2010?
body: <p>We have a set of DLLs written in C++ for Windows that are used by a C# application, and all of this is wrapped up in a Visual Studio solution. Now someone has ported the DLLs to Qt so they can be used on other OSs. Can I switch to the Qt code within my solution and continue to have it work with the C# app? Or will I have to split into two solutions?</p>
  
  <p>I've tried doing this already but when I try to build I get the errors </p>
  
  <blockquote>
    <p>"The operation could not be completed. The parameter is incorrect" </p>
  </blockquote>
  
  <p>or</p>
  
  <blockquote>
    <p>"Cannot perform requested action because a built is already in
    progress"</p>
  </blockquote>
  
  <p>FYI, I'm using the Qt V4.8.0 prebuilt binaries for VS2010.</p>