C# 调用C/C++ Dll（参数含char*指针，返回char*指针）

动态库：

//MyPointDll.h
extern"C" _declspec(dllexport) char* strcpyTest(char* dest,char* sour);

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

#include "stdafx.h"
#include "MyPointDll.h"

char* strcpyTest(char* dest,char* sour)
{ 
char* temp = dest;
while('\0' != *sour)
{
*dest = *sour;
dest++;
sour++;
}
*dest = '\0';
return temp;
}

C#调用Dll：

using System;
using System.Runtime.InteropServices;

namespace CSCallMyPointDll
{
    class Program
    {

        [DllImport(@"MyPointDll.dll", EntryPoint = "strcpyTest", CallingConvention = CallingConvention.Cdecl/*, CallingConvention = CallingConvention.Cdecl*/)]

        public static extern IntPtr strcpyTest(ref byte dest, string sour);

        static void Main(string[] args)
        {
            string strSour = "CS Call C Point Dll!";

            Byte[] bPara = new Byte[100];    //新建字节数组

            IntPtr pRet = strcpyTest(ref bPara[0], strSour);
            string strGet = System.Text.Encoding.Default.GetString(bPara, 0, bPara.Length);    //将字节数组转换为字符串
            string strRet = Marshal.PtrToStringAnsi(pRet);

            Console.WriteLine("源字符串：");
            Console.WriteLine(strSour);

            Console.WriteLine("传出值：");
            Console.WriteLine(strGet);

            Console.WriteLine("返回值：");
            Console.WriteLine(strRet);
        }
    }
}