在已经实现从主菜单场景切换到游戏场景的情况下，想要在游戏场景点击按钮后退回到主菜单
auto goItem = MenuItemImage::create(
“CloseNormal.png”,
“CloseSelected.png”,
CC_CALLBACK_1(GameScene::menuGoMain, this));
报错：
Undefined symbols for architecture i386:
“GameScene::menuGoMain(cocos2d::Ref*)”, referenced from:
GameScene::init() in GameScene.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)