求助：cocos2d-x3.0 LUA 的声音预加载

Cocos2d-x
#1 
   --1加载音乐  
 --cc.SimpleAudioEngine:getInstance():preloadBackgroundMusic("res/background.mp3")   --这句为注释
SimpleAudioEngine:getInstance():preloadEffect("res/background.mp3")  
 SimpleAudioEngine:getInstance():playBackgroundMusic("res/background.mp3",true)

不去掉注释程序正常运行，

去掉注释报错：
LUA ERROR: :20: attempt to call method ‘preloadBackgroundMusic’ (a nil value)

stack traceback:
:14: in function ‘preloadBackgroundMusic’
:20: in function ‘CreateLayer’
:28: in function ‘AmationTest’
:30: in function <:18>
: in function ‘xpcall’
:33: in main chunk
: in function ‘require’
:1: in main chunk

求大神解答

#2

:9:有人吗= =

#3

不 预加载 你怎么读取声音文件啊。

#4

预加载完成回调怎么写？

#5

楼主解决了吗