cocos2dx lua 热更新

最近研究cocos2dx + lua 实现游戏的热更新。基本原理：比如我有一个GameScene，显示"hello world",现在热更新，更新之后显示"hello SB".如果是用c++来开发，那么只用把它作成lib库，更新时替换lib库。用lua的话，更简单，替换相关的lua就可以了。

GameScene.lua

 require "Cocos2d"
 require "Cocos2dConstants"

 local GameScene = class("GameScene",function()
     return cc.Scene:create()
 end)

 function GameScene.create()
     local scene = GameScene.new()
     scene:addChild(scene:createTitle())
     return scene
 end


 function GameScene:ctor()
     self.visibleSize = cc.Director:getInstance():getVisibleSize()
     self.origin = cc.Director:getInstance():getVisibleOrigin()
     self.schedulerID = nil
 end

 function GameScene:createTitle()
     local title = cc.Label:createWithTTF("Hello World","fonts/arial.ttf",24)
     title:setPosition(self.visibleSize.width /2,self.visibleSize.height /2)

     return title
 end

更新的 GameScene.lua

 require "Cocos2d"
 require "Cocos2dConstants"

 local GameScene = class("GameScene",function()
     return cc.Scene:create()
 end)

 function GameScene.create()
     local scene = GameScene.new()
     scene:addChild(scene:createTitle())
     return scene
 end


 function GameScene:ctor()
     self.visibleSize = cc.Director:getInstance():getVisibleSize()
     self.origin = cc.Director:getInstance():getVisibleOrigin()
     self.schedulerID = nil
 end

 function GameScene:createTitle()
     local title = cc.Label:createWithTTF("Hello SB","fonts/arial.ttf",24)
     title:setPosition(self.visibleSize.width /2,self.visibleSize.height /2)

     return title
 end

最关键的更新模块，MenuScene.lua

 require "Cocos2d"
 require "Cocos2dConstants"

 local MenuScene = class("MenuScene",function()
     return cc.Scene:create()
 end)

 local title

 function MenuScene.create()
     local scene = MenuScene.new()
     scene:addChild(scene:createLayer())
     --scene:addChild(scene:createLayerFarm())
     --scene:addChild(scene:createLayerMenu())
     return scene
 end

 function MenuScene:ctor()
     self.visibleSize = cc.Director:getInstance():getVisibleSize()
     self.origin = cc.Director:getInstance():getVisibleOrigin()
     self.schedulerID = nil
 end



 function MenuScene:createLayer()

     function menuCallback1(tag)
         local scene = require("GameScene")
         local gameScene = scene.create()
         cc.Director:getInstance():replaceScene(gameScene)
     end

     function menuCallback2(tag)
         MenuScene:update()
     end

     local menuLayer = cc.Layer:create()
     title = cc.Label:createWithTTF("Choose Scene","fonts/arial.ttf",24)
     title:setPosition(self.visibleSize.width /2,self.visibleSize.height /4 * 3)
     menuLayer:addChild(title)

     local menuLabel1 = cc.Label:createWithTTF("Go to Scene", "fonts/arial.ttf", 24)
     local menuItem1 = cc.MenuItemLabel:create(menuLabel1)
     menuItem1:registerScriptTapHandler(menuCallback1)
     menuItem1:setPosition(self.visibleSize.width /2,self.visibleSize.height /4 * 2)


     local menuLabel2 = cc.Label:createWithTTF("Update", "fonts/arial.ttf", 24)
     local menuItem2 = cc.MenuItemLabel:create(menuLabel2)
     menuItem2:registerScriptTapHandler(menuCallback2)
     menuItem2:setPosition(self.visibleSize.width /2,self.visibleSize.height /4 * 1)

     local MainMenu = cc.Menu:create()
     MainMenu:setPosition(0,0)
     MainMenu:addChild(menuItem1)
     MainMenu:addChild(menuItem2)
     menuLayer:addChild(MainMenu)

     return menuLayer
 end

 function MenuScene:getAssetsManager()
     local function onError(errorCode)
         if errorCode == cc.ASSETSMANAGER_NO_NEW_VERSION then
             title:setString("no new version")
         elseif errorCode == cc.ASSETSMANAGER_NETWORK then
             title:setString("network error")
         end
     end

     local function onProgress( percent )
         local progress = string.format("downloading %d%%",percent)
         title:setString(progress)
     end

     local function onSuccess()
         title:setString("downloading ok")
     end

     local pathToSave          = ""
     pathToSave = createDownloadDir()

     local assetsManager = cc.AssetsManager:new("http://qd.baidupcs.com/file/1a531cc6565d95827e0ec3f9fd4af795?fid=138463011-250528-222085911919595&time=1406097600&sign=FDTAXER-DCb740ccc5511e5e8fedcff06b081203-mLvWIkhwaVZCjN%2BpTYZJZ%2BagPR4%3D&to=qb&fm=N,B,T,t&newver=1&expires=1406098200&rt=sh&r=164813188&mlogid=124796854&sh=1&vuk=138463011&vbdid=2986594979&fn=GameScene.zip",
         "https://raw.github.com/samuele3hu/AssetsManagerTest/master/version",
         pathToSave)
     assetsManager:retain()
     assetsManager:setDelegate(onError, cc.ASSETSMANAGER_PROTOCOL_ERROR )
     assetsManager:setDelegate(onProgress, cc.ASSETSMANAGER_PROTOCOL_PROGRESS)
     assetsManager:setDelegate(onSuccess, cc.ASSETSMANAGER_PROTOCOL_SUCCESS )
     assetsManager:setConnectionTimeout(3)
     return assetsManager
 end

 function MenuScene:update()
     MenuScene:getAssetsManager():update()
 end

 return MenuScene

关键看cc.AssertsMananger。cpp在extensions\assets-manager。

AssetsManager传三个参数，resource.zip路径，version路径，写文件的路径。

然后调用AssetsManager.update,进行下载更新。

注意的是，android时，它是写到Context.getCacheDir()里。所以每次进入游戏时，都会重新更新。需要修改 createDownloadDir()里创建的路径，把它写到sd卡上。