缺少c# / c++互操作性的入口点

我在我的程序上工作，我需要我的学士工作(c#/c++互操作性)，我有在我的代码中缺少入口点的问题…我尝试创建简单的数字生成器，它将在c++类中从c#调用生成数字…一开始我不知道如何通过一门课，但后来我在这页找到了方法……请帮我修一下……

我添加了代码:

#include <iostream>
#include <cstdlib>
#include <time.h>
using namespace std;

__declspec(dllexport) class Generator
    {
private:
    int zaciatok;
    int koniec;
    int pocetprvkov;
    int *pole;
public: 
      Generator(){}

      void Vytvor (int zaciatok, int koniec, int pocetprvkov)
    {
         srand((unsigned)time(0));
         pole= new int [pocetprvkov]; 
    }
       void Napln()
    {
        for(int a=0; a<pocetprvkov; a++)
          {
              pole[a] = rand() % (koniec - zaciatok +1) + zaciatok;
         }
    }
       void Vypis()
    {
        for(int a=0; a<pocetprvkov; a++)
        cout << pole[a] << endl;
    }
      ~Generator()
       {
           delete[] pole;
           pole= 0;
       }
    };
extern "C" 
{
 __declspec(dllexport) Generator* Vytvor_Triedu() { return new Generator(); }
 __declspec(dllexport) void Vytvor(Generator* prva) {prva->Vytvor(5,25,4); }
 __declspec(dllexport) void Napln(Generator* prva) {prva->Napln(); }
 __declspec(dllexport) void Vypis(Generator* prva) {prva->Vypis(); }
 __declspec(dllexport) void Vymaz(Generator* prva) { delete prva; }
} 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
namespace GeneratorCsharp
{
    class Program
    {
        [DllImport("DllTriedaGenerator.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern IntPtr Vytvor_Triedu();
        [DllImport("DllTriedaGenerator.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern void Vytvor(IntPtr value);
        [DllImport("DllTriedaGenerator.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern void Napln(IntPtr value);
        [DllImport("DllTriedaGenerator.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern void Vypis(IntPtr value);
        [DllImport("DllTriedaGenerator.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern void Vymaz(IntPtr value);
        static void Main(string[] args)
        {
            IntPtr trieda = Vytvor_Triedu();
            Vytvor(trieda);
            Napln(trieda);
            Vypis(trieda);
            Vymaz(trieda);

        }
    };
}

非常感谢!