// C++ Funktion in der DLL
int bigger(int a, int b)
{
	return (a > b ? a : b);
}
 
// Dann der C#-Code in meinem Programm
[DllImport("kernel32.dll")]
public static extern IntPtr LoadLibrary(string lpFileName);
[DllImport("kernel32.dll")]
public static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
[DllImport("kernel32.dll")]
public static extern bool FreeLibrary(IntPtr hModule);
 
private delegate int Bigger(int a, int b);
 
public static void Test()
        {
            IntPtr hDLL = LoadLibrary("[PFAD+DLL]");
            IntPtr Func = GetProcAddress(hDLL, "bigger");
            Bigger b = (Bigger)Marshal.GetDelegateForFunctionPointer(Func, _
              typeof(Bigger));
            int result= b(1, 2);
            FreeLibrary(hDLL);
        }