1 纹理从文件中读取
local img = display.newSprite("1.png")
img:setTexture("2.png")
2 纹理从缓存中读取
display.addSpriteFramesWithFile("1.plist","1.png")
local frame = display.newSpriteFrame("xx.png")
local img = display.newSprite(frame)
frame = display.newSpriteFrame("xxx.png")
img:setDisplayFrame(frame)
