cocos2d-Lua与c++交互，lua如何绑定C++类。

我们有一个C++类，TestLayer.h

#ifndef __TEST_LAYER_H__
#define __TEST_LAYER_H__

#include "cocos2d.h"

namespace cocos2d{

	class TestLayer : public Layer
	{
	public:

		static TestLayer* create();
		bool init();

		void myPrint(const std::string &str);

		TestLayer(void);
		~TestLayer(void);
	};

}
int register_TestLayer(lua_State* tolua_S);

#endif

TestLayer.cpp

#include "TestLayer.h"
using namespace cocos2d;

TestLayer::TestLayer()
{
}


TestLayer::~TestLayer()
{
}

void TestLayer::myPrint(const std::string &str)
{
	CCLOG(str.c_str());
}

TestLayer* TestLayer::create()
{
	TestLayer *pRet = new TestLayer();
	if ( pRet && pRet->init() ) {
        pRet->autorelease();
        return pRet;
    }
    CC_SAFE_DELETE(pRet);
    return nullptr;
}

bool TestLayer::init()
{
	if ( !Layer::init() ) {
		return false;
	}

	return true;
}


//lua binding
#include "tolua_fix.h"
#include "LuaBasicConversions.h"

int lua_cocos2dx_TestLayer_create(lua_State* tolua_S)
{
    int argc = 0;
    bool ok  = true;

#if COCOS2D_DEBUG >= 1
    tolua_Error tolua_err;
#endif

#if COCOS2D_DEBUG >= 1
    if (!tolua_isusertable(tolua_S,1,"cc.TestLayer",0,&tolua_err)) goto tolua_lerror;
#endif

    argc = lua_gettop(tolua_S) - 1;

    if (argc == 0)
    {
        if(!ok)
        {
            tolua_error(tolua_S,"invalid arguments in function 'lua_cocos2dx_TestLayer_create'", nullptr);
            return 0;
        }
        TestLayer* ret = TestLayer::create();
        object_to_luaval<TestLayer>(tolua_S, "cc.Layer",(TestLayer*)ret);
        return 1;
    }
    luaL_error(tolua_S, "%s has wrong number of arguments: %d, was expecting %d\n ", "cc.Layer:create",argc, 0);
    return 0;
#if COCOS2D_DEBUG >= 1
    tolua_lerror:
    tolua_error(tolua_S,"#ferror in function 'lua_cocos2dx_TestLayer_create'.",&tolua_err);
#endif
    return 0;
}

int lua_cocos2dx_TestLayer_myPrint(lua_State* tolua_S)
{
    int argc = 0;
	TestLayer* cobj = nullptr;
    bool ok  = true;

#if COCOS2D_DEBUG >= 1
    tolua_Error tolua_err;
#endif


#if COCOS2D_DEBUG >= 1
    if (!tolua_isusertype(tolua_S,1,"cc.TestLayer",0,&tolua_err)) goto tolua_lerror;
#endif

    cobj = (cocos2d::TestLayer*)tolua_tousertype(tolua_S,1,0);

#if COCOS2D_DEBUG >= 1
    if (!cobj) 
    {
        tolua_error(tolua_S,"invalid 'cobj' in function 'lua_cocos2dx_TestLayer_myPrint'", nullptr);
        return 0;
    }
#endif

    argc = lua_gettop(tolua_S)-1;
    if (argc == 1) 
    {
        std::string arg0;

        ok &= luaval_to_std_string(tolua_S, 2,&arg0, "cc.TestLayer:myPrint");
        if(!ok)
        {
            tolua_error(tolua_S,"invalid arguments in function 'lua_cocos2dx_TestLayer_myPrint'", nullptr);
            return 0;
        }
        cobj->myPrint(arg0);
        lua_settop(tolua_S, 1);
        return 1;
    }
    luaL_error(tolua_S, "%s has wrong number of arguments: %d, was expecting %d \n", "cc.TestLayer:myPrint",argc, 1);
    return 0;

#if COCOS2D_DEBUG >= 1
    tolua_lerror:
    tolua_error(tolua_S,"#ferror in function 'lua_cocos2dx_TestLayer_myPrint'.",&tolua_err);
#endif

    return 0;
}

int lua_register_cocos2dx_TestLayer(lua_State* tolua_S)
{
    tolua_usertype(tolua_S,"cc.TestLayer");
    tolua_cclass(tolua_S,"TestLayer","cc.TestLayer","cc.Layer",nullptr);

    tolua_beginmodule(tolua_S,"TestLayer");
        tolua_function(tolua_S,"create", lua_cocos2dx_TestLayer_create);
				tolua_function(tolua_S,"myPrint",lua_cocos2dx_TestLayer_myPrint);

    tolua_endmodule(tolua_S);
    std::string typeName = typeid(TestLayer).name();
    g_luaType[typeName] = "cc.TestLayer";
    g_typeCast["TestLayer"] = "cc.TestLayer";
    return 1;
}

int register_TestLayer(lua_State* tolua_S)
{
	lua_getglobal(tolua_S, "_G");
    if (lua_istable(tolua_S,-1))//stack:...,_G,
    {
        tolua_open(tolua_S);
		
		tolua_module(tolua_S,"cc",0);
		tolua_beginmodule(tolua_S,"cc");

		lua_register_cocos2dx_TestLayer(tolua_S);

		tolua_endmodule(tolua_S);
    }
    lua_pop(tolua_S, 1);
    
    return 1;
}

这样就写好了一个c++类及其绑定函数，然后我们在Appdelegate.cpp中加入如下代码

bool AppDelegate::applicationDidFinishLaunching()
{
    // set default FPS
    Director::getInstance()->setAnimationInterval(1.0 / 60.0f);
   
    // register lua module
    auto engine = LuaEngine::getInstance();
    ScriptEngineManager::getInstance()->setScriptEngine(engine);
    lua_State* L = engine->getLuaStack()->getLuaState();
    lua_module_register(L);
	register_TestLayer(L);

    // If you want to use Quick-Cocos2d-X, please uncomment below code
    // register_all_quick_manual(L);

    LuaStack* stack = engine->getLuaStack();
    stack->setXXTEAKeyAndSign("2dxLua", strlen("2dxLua"), "XXTEA", strlen("XXTEA"));
    
    //register custom function
    //LuaStack* stack = engine->getLuaStack();
    //register_custom_function(stack->getLuaState());
    
#if (COCOS2D_DEBUG > 0) && (CC_CODE_IDE_DEBUG_SUPPORT > 0)
    // NOTE:Please don't remove this call if you want to debug with Cocos Code IDE
    RuntimeEngine::getInstance()->start();
    cocos2d::log("iShow!");
#else
    if (engine->executeScriptFile("src/main.lua"))
    {
        return false;
    }
#endif
    
    return true;
}

OK，大功告成，我们只要在lua文件中做如下调用进行测试：

local MainScene = class("MainScene", cc.load("mvc").ViewBase)

function MainScene:onCreate()
    -- add background image
    display.newSprite("MainSceneBg.jpg")
        :move(display.center)
        :addTo(self)

    -- add play button
    local playButton = cc.MenuItemImage:create("PlayButton.png", "PlayButton.png")
        :onClicked(function()
            --self:getApp():enterScene("PlayScene")
             local layer = cc.TestLayer:create()
             layer:myPrint("哈哈")
        end)


    cc.Menu:create(playButton)
        :move(display.cx, display.cy - 200)
        :addTo(self)
end

return MainScene

可以看到，lua文件中，成功打印“哈哈”