先上代码:

#include "stdafx.h"
#include<iostream>
#include "luabind\luabind.hpp"

extern "C"


{
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"
}

using namespace std;

bool LoadScript(lua_State *L,const string& fname)


{
if (luaL_dofile(L,fname.c_str()))

{
cerr<<lua_tostring(L,-1)<<endl;
return false;
}
return true;
}

void testFunc(int k)


{
cout<<"hello there, i am a cpp fun"<<endl;
cout<<"input num:="<<k<<endl;
}


class NumberPrinter
{
public:
NumberPrinter(int number) :

m_number(number)
{}


void print()
{
cout << m_number << endl;
}

private:
int m_number;
};


int _tmain(int argc, _TCHAR* argv[])


{
using namespace luabind;
lua_State* L = luaL_newstate();
module(L, "cppapi")
[
def("testFunc", (void(*)(int))testFunc)
];

// 使用LuaBind导出NumberPrinter类
luaopen_base(L);
luabind::open(L);

luabind::module(L)
[
luabind::class_<NumberPrinter>("NumberPrinter")
.def(luabind::constructor<int>())
.def("print", &NumberPrinter::print)
];
luaL_openlibs(L);
LoadScript(L,"test.lua");

try
{
int add_ret = luabind::call_function<int>(L,"add",10,4);
int call_global = luabind::object_cast<int>(luabind::globals(L)["nGlobal"]);
string strGlobal = luabind::object_cast<string>(luabind::globals(L)["strGlobal"]) ;
luabind::object lua_object = luabind::globals(L)["t"];
//--2种办法load table
string strName = luabind::object_cast<string>(lua_object["name"]);
int iAge = luabind::object_cast<int>(lua_object["age"]);
string strElse = luabind::object_cast<string>(lua_object["desc"]);
}
catch(luabind::error& e)

{
cout<<e.what()<<endl;
printf("AI throw error: err_msg[%s]", lua_tostring(L, -1));
return false;
}
lua_close(L);
return 0;
}其中test.lua的代码如下:
Print2000 = NumberPrinter(2000)
Print2000:print()
nGlobal = 10 --一个全局的整形变量
strGlobal = "hello i am in lua" --一个全局的字符串变量
--一个返回值为int类型的函数
function add(a, b)
return a+b
end
--一个返回值为string类型的函数
function strEcho(a)
print(a)
return 'haha i h
ave print your input param'
end
cppapi.testFunc(10) --调用c++暴露的一个测试函数
t={name='ettan', age=23, desc='正值花季年龄'}
运行结果为:

这上面luabind调用c++函数的实例:调用testFunc函数;也有c++调用lua的代码,具体的见代码。
此代码在我的vs2010上面调试通过,前提是必须配好环境如:添加依赖库luabind.debug.lib;lua.debug.lib
添加依赖库路径。
特别注意:
首先Lua是“动态编译的脚本语言”,而loadfile只是把源文件加载到内存中,还少了“编译”这一步,可以用“luaL_dofile(L,"test.lua");”来替换,它既加载又编译。替换之后执行应该就没有问题了。
但是还没完,luaL_dofile 实际上是个宏:
- #define luaL_dofile(L, fn) \
- (luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0))
LUA_MULTRET也是宏定义,值为-1,表示函数有多个返回值(Lua规则,pil 24.2--堆栈)。
扩展开来就是以下两句:
- luaL_loadfile(L, fn);
- lua_pcall(L, 0, LUA_MULTRET, 0);
pcall以上述参数执行的时候,会把加载到内存中的源程序编译成可以用于执行的2进制代码,并将全局变量压栈(在Lua中,函数也是变量,pil 2.5 -- Functions,毕竟函数名和函数体是不同的2个东西)。就跟PE文件格式里的Section一样(PE文件就是Windows3.1之后的.exe/.dll文件)。当然如果你不知道什么PE文件也没关系--我只是打个比方--就当成VS2005编译代码时生成的.obj文件。
虽然实际使用中99%的情况都是直接使用dofile,但是我想将该问题提出来说可以更加直观的理解“动态编译”。
参照:
代码和文字大部分出自 1. http://blog.csdn.net/caoyanting007/article/details/5709820
2. http://mobile.51cto.com/iphone-285654.htm