C#调C++动态库Dll C++回调C#函数

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1. vs2010 新建项目 / Visual C++ / 类库； 项目名  MyCallbackDll

头文件：

定义类 成员函数

​

\

// MyCallbackDll.h

#pragma once

using namespace System;

#ifdef DLL
#define DLL_API __declspec(dllexport)
#else
#define DLL_API
#endif

namespace MyCallbackDll 
{

	public DLL_API class ClassDll
	{
		// TODO: 在此处添加此类的方法。
	public:
		int Add(int a,int b);
		//{
		//	return a + b;		
		//}
	};
}

开放函数接口

#include "StdAfx.h"
//#include "MyCallbackDll.h"

using namespace MyCallbackDll;

typedef int (*Operate)(int a, int b);  //函数指针，   回调C#函数， 传入参数 传出结果
static Operate pOptFun;                //

extern "C" __declspec(dllexport) int ExportAdd(int x,int y);

//注册回调
extern "C" __declspec(dllexport) void RegistCallback(Operate opt);

//回调测试
extern "C" __declspec(dllexport) int TestOperateCallback(int x,int y);



//////////////////////////////////////////////////////////////////////////////////////


char* pStr = "very good!!!";

typedef int (*pFunOutputStr)(char* pOut);  //函数指针， 回调C#函数，传出字符串
static pFunOutputStr pOutputFun;

//注册回调
extern "C" __declspec(dllexport) void RegistOutputStrCallback(pFunOutputStr opt);

//回调测试
extern "C" __declspec(dllexport) void TestOutputString();

源文件：

实现类成员函数

// 这是主 DLL 文件。

#include "stdafx.h"

#include "MyCallbackDll.h"

using namespace  MyCallbackDll;

int ClassDll::Add(int a,int b)
{
	return a + b;		
}

对外接口实现：

#include "StdAfx.h"
#include "MyCallbackDll.h"
#include "ExportDll.h"

using namespace MyCallbackDll;


int ExportAdd(int x,int y)
{
	ClassDll* pCDll;	
	return pCDll->Add(x,y);
}


//注册回调
void RegistCallback(Operate opt)
{
	pOptFun = opt;
}

//回调测试
int TestOperateCallback(int x,int y)
{	
	return pOptFun(x, y);;
}


//////////////////////////////////////////////////////////////////////////////////////


//注册回调
void RegistOutputStrCallback(pFunOutputStr opt)
{
	pOutputFun = opt;
}

//回调测试
void TestOutputString()
{
	pOutputFun(pStr);
}

2. vs2010 新建项目 / Visual C# / 控制台应用程序； 项目名  TestMyCallbackDll
​

引入动态库 MyCallbackDll.dll

using System.Runtime.InteropServices;

namespace TestMyCallbackDll
{
    class ImportDll
    {

        [DllImport("MyCallbackDll.dll", EntryPoint = "ExportAdd", CallingConvention = CallingConvention.Cdecl)]
        public static extern int ExportAdd(int a, int b);

        //测试回调  
        public delegate int OperateDelegate(int a, int b);

        [DllImport("MyCallbackDll.dll", EntryPoint = "RegistCallback", CallingConvention = CallingConvention.Cdecl)]
        public static extern void RegistCallback(OperateDelegate opeDelegate);

        [DllImport("MyCallbackDll.dll", EntryPoint = "TestOperateCallback", CallingConvention = CallingConvention.Cdecl)]
        public static extern int TestOperateCallback(int a, int b);


        //回调 传字符串

        public delegate void OutputStrDelegate(string str);

        [DllImport("MyCallbackDll.dll", EntryPoint = "RegistOutputStrCallback", CallingConvention = CallingConvention.Cdecl)]
        public static extern void RegistOutputStrCallback(OutputStrDelegate output);

        [DllImport("MyCallbackDll.dll", EntryPoint = "TestOutputString", CallingConvention = CallingConvention.Cdecl)]
        public static extern void TestOutputString();
        
    }

}

调用Dll 函数接口，及回调测试：

using System;

namespace TestMyCallbackDll
{
    class Program
    {
        //static bool bIsRun = true;
        ////public extern class ClassDll;
        //static IntPtr pt;

        static void Main(string[] args)
        {

            int iAddRet = ImportDll.ExportAdd(3, 7);
            Console.WriteLine("{0} + {1} = {2}", 3, 7, iAddRet);

            ImportDll.OperateDelegate od = new ImportDll.OperateDelegate(SubOperate);
            ImportDll.RegistCallback(od);
            int iCallbackRet = ImportDll.TestOperateCallback(5, 3);
            Console.WriteLine("{0} - {1} = {2}", 5, 3, iCallbackRet);

            ImportDll.OutputStrDelegate outputDelegate = new ImportDll.OutputStrDelegate(GetStringCallBack);
            ImportDll.RegistOutputStrCallback(outputDelegate);
            ImportDll.TestOutputString();

        }

        static string outputStr = null;
        public static void GetStringCallBack(string strRet)
        {
            outputStr = strRet;
            Console.WriteLine(outputStr);
            Console.WriteLine("test good!!");
        }

        public static int SubOperate(int a, int b)
        {
            return a - b;
        }

    }
}

​