C++类对象与Lua之间的交互

C++类对象与Lua之间的交互

  C语言与Lua进行交互，我们可以相对轻易的做到，但在实际应用中我们更加偏向于使用C++与Lua进行交互，面向对象编程。

关于C语言与Lua之间的调用交互实例可参考以下文章：

https://ufgnix0802.blog.csdn.net/article/details/125137333

https://ufgnix0802.blog.csdn.net/article/details/125193301

https://ufgnix0802.blog.csdn.net/article/details/125287026

这里不写过多注释进行阐释。

main.cpp

#include <iostream>
#include <string>
#include "lua.hpp"

#define LUA_CLASS_A "LUA_CLASS_A"

class A {
public:
    bool Init(int a, const char* str) {
        m_a   = a;
        m_str = str;
        return true;
    }

    bool Print() {
        std::cout << "str:" << m_str 
            << " a:" << m_a << std::endl;
        return true;
    }

    bool UnInit() {
        std::cout << "UnInit" << std::endl;
        return true;
    }

private:
    int         m_a;
    const char* m_str;
};

extern "C" {
    static int InitA(lua_State* L) {
        A* pA = (A*)luaL_checkudata(L, 1, LUA_CLASS_A);

        int a = luaL_checkinteger(L, 2);
        const char* str = luaL_checkstring(L, 3);

        pA->Init(a, str);

        lua_pop(L, 3);
        return 0;
    }


    static int UnInitA(lua_State* L) {
        A* pA = (A*)luaL_checkudata(L, 1, LUA_CLASS_A);

        pA->UnInit();

        lua_pop(L, 1);
        return 0;
    }

    static int PrintA(lua_State* L) {
        A* pA = (A*)luaL_checkudata(L, 1, LUA_CLASS_A);
        pA->Print();

        lua_pop(L, 1);
        return 0;
    }

    static int CreateA(lua_State* L) {
        A* pA = (A*)lua_newuserdata(L, sizeof(A));
        luaL_setmetatable(L, LUA_CLASS_A);
        return 1;
    }
}


static const luaL_Reg AFuncs[] = {
    {"Init",  InitA},
    {"__gc",  UnInitA},
    {"PrintA",PrintA},
    {NULL,    NULL}
};

static void CreateMetaTable(lua_State* L) {
    luaL_newmetatable(L, LUA_CLASS_A);
    lua_pushvalue(L, -1);
    lua_setfield(L, -2, "__index");
    luaL_setfuncs(L, AFuncs, 0);
    lua_pop(L, 1);
}


int main(int argc, char** argv) {
    lua_State* L = luaL_newstate();  /* create state */

    luaL_openlibs(L);

    CreateMetaTable(L);

    lua_pushcfunction(L, CreateA);
    lua_setglobal(L, "CreateA");

    if (luaL_dofile(L, "main.lua")) {
        printf("%s\n", lua_tostring(L, -1));
    }
    
    // 执行完成后关闭lua虚拟机
    lua_close(L);
    return EXIT_SUCCESS;
}

main.lua

local A = CreateA()

A:Init(1234,"hello")
A:PrintA()

输出结果