WPF.NET app 86 with C++ dll 86

MyClass.cpp:
int MyClass::Foo_1()
{
    __asm
  {
    mov eax, 0
  }
}
void MyClass::SetFoo_1()
{
  resultEAX = new int;
  int a = -1;
  try
  {
    a = Foo_1();
  }
  catch (int e) { }
  if (a == 0) {
  *resultEAX = 0;
  }
  else {
    *resultEAX = 1;
  }
}

MyClass.h:
#ifndef MYCLASS_H
#define MYCLASS_H
class __declspec(dllexport) MyClass {
public:
int * resultEAX ;
int Foo1();
void SetFoo_1();
int  GetEAX();
};
#endif

**
MyClassCaller.h:
extern "C" {
#endif
__declspec(dllexport) MyClass* Create();
__declspec(dllexport) void Dispose(MyClass* a_pObject);
__declspec(dllexport) void SetFoo_1(MyClass* a_pObject);
__eclspec(dllexport) int GetEAX(MyClass* a_pObject);
#ifdef __cplusplus
}
#endif

**
MyClassCaller.cpp:
Graphics* Create()
{
  return new MyClass();
}

void Dispose(MyClass * a_pObject)
{
  if (a_pObject != NULL)
  {
    delete a_pObject;
    a_pObject = NULL;
  }
}

void SetFoo_1(MyClass * a_pObject)
{
  if (a_pObject != nullptr)
  {
    a_pObject->SetFoo_1();
  }
}

int GetEAX(MyClass * a_pObject)
{
  if (a_pObject != NULL)
  {
     return a_pObject->GetEAX();
}
return 0;
}

And I call the class from WPF .NET using managed C# code:
IntPtr pMyClass = MyClassHandling.Create();
Int32 a = 0;
Int64 b = 0;
long c = 0;
long rslt = 0;

try
{
  MyClassHandling.SetFoo_1(pMyClass);
  if (Environment.Is64BitOperatingSystem)
  {
    //"SysWOW64"
    b = MyClassHandling.GetEAX(pMyClass);
……
  }
  else
  {
    //"system32"
    a = pMyClassHandling.GetEAX(pGraphics);
    …
  }

MyClassHandling.Dispose (pGraphics);
pMyClass = IntPtr.Zero;
**

[DllImport("SomeAssemblerFunctions.dll")]
static public extern IntPtr Create();
[DllImport("SomeAssemblerFunctions.dll")]
static public extern void Dispose(IntPtr pGraphicsObject);
[DllImport("SomeAssemblerFunctions.dll"
, EntryPoint = "SetGraphicMode1")]
static public extern void SetFoo_1(IntPtr pGraphicsObject);
[DllImport("SomeAssemblerFunctions.dll"
, EntryPoint = "GetEAX")]
static public extern int GetEAX(IntPtr pGraphicsObject);