Call c++ function pointer from c#

c#, c++, function-pointers

Solution

dtb is right. Here a more detailed example for Marshal.GetDelegateForFunctionPointer. It should work for you.

In C++:

static int __stdcall SomeFunction(void* someObject, void*  someParam)
{
  CSomeClass* o = (CSomeClass*)someObject;
  return o->MemberFunction(someParam);
}

int main()
{
  CSomeClass o;
  void* p = 0;
  CSharp::Function(System::IntPtr(SomeFunction), System::IntPtr(&o), System::IntPtr(p));
}

In C#:

public class CSharp
{
  delegate int CFuncDelegate(IntPtr Obj, IntPtr Arg);
  public static void Function(IntPtr CFunc, IntPtr Obj, IntPtr Arg)
  {
    CFuncDelegate func = (CFuncDelegate)Marshal.GetDelegateForFunctionPointer(CFunc, typeof(CFuncDelegate));
    int rc = func(Obj, Arg);
  }
}

Problem

Is it possible to call a c(++) static function pointer (not a delegate) like this ``` typedef int (*MyCppFunc)(void* SomeObject); ``` from c#? ``` void CallFromCSharp(MyCppFunc funcptr, IntPtr param) { funcptr(param); } ``` I need to be able to callback from c# into some old c++ classes. C++ is managed, but the classes are not ref classes (yet). So far I got no idea how to call a c++ function pointer from c#, is it possible?

Original source

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