求问如何解决的。。跟着老师代码一模一样。但是没有出现body

其实我也是新手，但是我看了一下，它好像是说你的node给了一个数值，你可以去MainScene那看一下snake的创建是不是self.snake = Snake.new(self)，大概是这个原因吧

local Snake = class("Snake")

local Body = require "app.Body"

local cInitLen = 3

function Snake:ctor( node )

self.BodyArray = {}

self.node = node

self.MoveDir = "left"

for i=1,cInitLen do

self:Grow(i ==1)

end

end

function Snake:GetTailGrid()

if #self.BodyArray == 0 then

return 0,0

end

local tail = self.BodyArray[#self.BodyArray]

return tail.X,tail.Y

end

function Snake:Grow( isHead )

local tailX,tailY = self:GetTailGrid()

local body = Body:new(self,tailX,tailY,self.node,isHead)

table.insert(self.BodyArray,body)

end

local function OffsetGridByDir( x,y,dir )

if dir == "left" then

return x-1,y

elseif dir == "right" then

return x+1,y

elseif dir == "up" then

return x,y-1

elseif dir == "down" then

return x,y+1

end

print("unknown dir",dir)

return x,y

end

function Snake:Update()

if #self.BodyArray == 0 then

return 0,0

end

for i = #self.BodyArray,1,-1 do

local body = self.BodyArray[i]

if i == 1 then

body.X,body.Y = OffsetGridByDir(body.X,body.Y,self.MoveDir)

else

local front = self.BodyArray[i-1]

body.X,body.Y = front.X,front.Y

end

body:Update()

end

end

return Snake

local Body = class("Body")

local cGridSize = 33

local scaleRate = 1/display.contentScaleFactor

function Grid2Pos( x,y )

local visibleSize = cc.Director:getInstance():getVisibleSize()

local origin = cc.Director:getInstance():getVisibleOrigin()

local finalX = origin.x+visibleSize.width/2+x*cGridSize*scaleRate

local finalY = origin.y+visibleSize.height/2+y*cGridSize*scaleRate

return finalX,finalY

end

function Body:ctor( snake,x,y,node,isHead )

self.snake = snake

self.X = x

self.Y = y

if ishead then

self.sp = cc.Sprite:create("head_l.png")

else

self.sp = cc.Sprite:create("body.png")

end

node:addChild(self.sp)

self:Update()

end

function Body:Update()

local posx,posy = Grid2Pos(self.X,self.Y)

self.sp:setPosition(posx,posy)

end

return Body