Ninjatrader.com provides a dll (NinjaTrader.Client.dll) along with their trading platform which allows third party API's to send orders (among other things) to their trading platform. The dll is a managed .Net dll. Here is a typical function:
int Ask(string instrument, double price, int size)
Sets the ask price and size for the specified instrument. A return value of 0 indicates success and -1 indicates an error.
What would the code in a C++ dll look like which would call that function and return its value to another application. Never mind what the other application has to do to communicate with the C++ dll.All I can tell you about the other application is that it can only communicate with dll's that use the __stdcall calling convention.
Neither this
WRAPPERLIBRARY_API wchart_t __stdcall MySayHelloWrapper(void);
nor this
WRAPPERLIBRARY_API wchart_t __stdcall MySayHelloWrapper(wchar_t *parameter);