Question

I have a native regular C++ Dll which I want to call from C# code, so i created C++/CLI class (as described here and here) which will include managed C++ code and which can be called by any C# code directly and which can make calls inturn to native unmanaged C++.

One of function in native C++ dll has parameter of type int *. How do I declare in wrapper function and how can i convert it into int *?

Answer 1

[DllImport("some.dll")]
static extern void SomeCPlusPlusFunction(IntPtr arg);

IntPtr is a type that is roughly equivalent to void *.

From your comment, you’d be best off doing something like this (C#):

int size = 3;
fixed (int *p = &size) {
    IntPtr data = Marshal.AllocHGlobal(new IntPtr(p));
    // do some work with data
    Marshal.FreeHGlobal(data); // have to free it
}

but since AllocHGlobal can take an int, I don’t know why you wouldn’t do this:

IntPtr data = Marshal.AllocHGlobal(size);