利用lua 中的table 特性
Base = {x = 0,y = 0}
Base.name = "luohai"
Base.age = 12
Base.sex = "man"
Base.new = function(self)
local ower = {}
setmetatable(ower,self)
self.__index = self
return ower
end
Base.setXY = function(self,x,y)
self.x = x;
self.y = y;
end