C# 调用C++ dll

参考：http://www.soaspx.com/dotnet/csharp/csharp_20110406_7469.html

测试代码：

using System;
using System.Runtime.InteropServices;

namespace CsharpDemo
{
    class CppDll
    {
        //传入int 型
        [DllImport("CsharpInvokeCpp.dll")]
        public static extern int Add(int x, int y);

        [DllImport("CsharpInvokeCpp.dll")]
        public static extern int Sub(int x, int y);

        //x,y的值使用后将改变
        [DllImport("CsharpInvokeCpp.dll")]
        public static extern int SumEditor(ref int x, ref int y);

        //DLL 需传入char* 类型 
        [DllImport("CsharpInvokeCpp.dll")]
        public static extern int CharRef(string a, string b);


        // 返回对象
        [DllImport("CsharpInvokeCpp.dll")]
        public static extern IntPtr Create(string name, int age);

        [StructLayout(LayoutKind.Sequential)]
        public struct User
        {
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
            public string Name;

            public int Age;
        }

    }
}

 

using System;
using System.Runtime.InteropServices;

namespace CsharpDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            int result = CppDll.Add(4, 33);
            Console.WriteLine(result.ToString());

            int a = 10;
            int b = 5;
            Console.WriteLine(CppDll.SumEditor(ref a,ref b));
            Console.WriteLine(a.ToString());

            IntPtr ptr = CppDll.Create("李平", 27);

            CppDll.User user = (CppDll.User)Marshal.PtrToStructure(ptr, typeof(CppDll.User));

            Console.WriteLine(user.Name);

            Console.ReadLine();

        }
    }
}

 

// CsharpInvokeCpp.cpp : 定义 DLL 应用程序的导出函数。
//

#include "stdafx.h"
#include "malloc.h"
#include "userinfo.h"


extern "C" __declspec(dllexport) int __stdcall    Add(int x,int y){

    return  x+y;

}

extern "C" __declspec(dllexport) int __stdcall  Sub(int x,int y){

    return  x-y;

}

extern "C" __declspec(dllexport) int __stdcall  SumEditor(int *x ,int *y){
    *x=100;
    *y=50;
    return  *x + *y;
}

extern "C" __declspec(dllexport) int __stdcall  CharRef(char* a,char* b){

    return  1;
}

typedef struct {
    char name[32];
    int age;
}User;

UserInfo* userInfo;

extern "C" __declspec(dllexport) User*  __stdcall Create(char* name, int age)    
{   
   User* user = (User*)malloc(sizeof(User));
   userInfo = new UserInfo(name, age);
   strcpy(user->name, userInfo->GetName());  
   user->age = userInfo->GetAge();
   return user; 
}

#include "StdAfx.h"
#include "UserInfo.h"


UserInfo::UserInfo(char* name, int age)
{
    m_Name = name; 
    m_Age = age;
}


UserInfo::~UserInfo(void)
{
}


int UserInfo::GetAge()
{ 
    return m_Age; 
}
char* UserInfo::GetName()
{ 
    return m_Name; 
}