C#调用C++动态库接口函数和回调函数方法

//带返回值无形参示例
EXTERN_C TOOLLIBRARY_api char* Version(void);
//无返回值带指针形参示例
EXTERN_C TOOLLIBRARY_API void SetApplicationDirPath(char *buff);

char* Version(void)
{
    return version_str;
}

void SetApplicationDirPath(char * buff)
{
    std::string str = buff;
    printf("传入的参数:%s\n", buff);
    std::cout << "字符串:"<<buff <<std::endl;
}

namespace CSharp_LoadLibrary
{
    class Program
    {
        [DllImport("TOOLLIBRARY.dll", EntryPoint = "Version", CharSet = CharSet.Ansi, CallinGConvention = CallingConvention.Cdecl)]
        extern static IntPtr Version();

        [DllImport("TOOLLIBRARY.dll", EntryPoint = "SetApplicationDirPath", CallingConvention = CallingConvention.Cdecl)]
        extern static void SetApplicationDirPath(IntPtr text);
        
        static void Main(string[] args)
        {
            //传入参数--测试
            SetApplicationDirPath(Marshal.StringToHGlobalAnsi("传入字符串测试.."));

            //打印返回值测试
            Console.WriteLine(Marshal.PtrToStringAnsi(Version()));
        }
    }
}

//设置回调函数指针
EXTERN_C TOOLLIBRARY_API void Set_DebugCallBackFunction(void(*func)(const char *p));

//C++的回调函数
void Set_DebugCallBackFunction(void(*func)(const char *p))
{
    //设置回调函数指针
    CallBackFunction_p = func;
    printf("回调函数设置成功.\n");
    CallBackFunction_p("这是回调函数传出来的测试数据.\n");
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;

namespace CSharp_LoadLibrary
{
    class Program
    {
        [DllImport("TOOLLIBRARY.dll", EntryPoint = "Set_DebugCallBackFunction", CallingConvention = CallingConvention.Cdecl)]
        extern static int Set_DebugCallBackFunction(CallbackDelegate callback);
        
        //定义委托
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        public delegate void CallbackDelegate(IntPtr Path);

        //接收C++回调数据
        //当C++调用传递过去的函数指针时，就会执行下面这个方法
        static void CallBackFunction(IntPtr Path)
        {
            Console.WriteLine("C++传出来的回调:" + Marshal.PtrToStringAnsi(Path));
        }

        static void Main(string[] args)
        {
            //调用C++设置回调函数的接口，将C#的函数地址传递过去
            Set_DebugCallBackFunction(CallBackFunction);
        }
    }
}