C / C++ / MFC

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

typedef struct St
{
     int a;
     int b;
}

__declspec(dllexport) void SetMyStruct( St* s );

--Now, in your c# code you would do the following:

[System.Runtime.InteropServices.LayoutKind(LayoutKindSequential)]
public struct St
{
    public int a;
    public int b;
}

public class MyClass
{
    [DllImport("mydll.dll")]
     public static extern void SetMyStruct( ref St s );
}