Question

I’m trying to write a WPF application which uses a function defined in C++. The C++ application is compiled as a DLL.

What I’m doing is using the DllImport attribute to import the function and use it. This works fine on my machine but when I attempt to run my WPF application on another machine it gives a “cannot find the DLL” error.

An excerpt of my C# (WPF) code:

[DllImport("Dll.dll")]
public static extern int MyFunc();

public MainWindow()
{
  InitializeComponent();
  MessageBox.Show("Starting");
  try
  {
    MessageBox.Show(MyFunc().ToString());
  }
  catch (Exception exc)
  {
    while (exc != null)
    {
      MessageBox.Show(exc.Message);
      exc = exc.InnerException;
    }
}

My C++ code:

extern "C" __declspec(dllexport) int MyFunc() {
  return 3;
}

Can anyone see where my error might be?

Thanks in advance for your help!

EDIT: It would appear that the issue is that the dependency “MSVCR100D” isn’t present. My understanding is that this is a file in the VC++ Redistributable package which I have installed by to no avail.

Answer 1

Your DLL might depend on other DLLs that are not installed on the other machine. You can check the dependencies with Dependency Walker.

Typical missing dependencies are the Visual Studio C/C++ Runtime libraries. If they are missing, just google for it. Microsoft offers redistributable packages for them.