lua 面向对象(继承、封装、多态)

• 封装

  Object={}
  Object.id=1
  
  function Object:new()
  	local obj = {}
  	self.__index=self
  	setmetatable(obj,self)
  	return obj
  end
  
  local  myObj = Object:new()
  myObj.id=3
  print(myObj)
  print(Object)
  print(myObj.id)
  

• 继承

  obj.base=self 保存基类方法

  function Object:SubClass(className)
       _G[className]={}
       local obj=_G[className]
       self.__index=self
       obj.base=self
       setmetatable(obj,self)
  end
  Object:SubClass("Person")
  local p1 = Person:new()
  print(p1.id)
  
  

• 多态

  
  Object:SubClass("GameObject")
  GameObject.posX=0
  GameObject.posY=0
  
  function GameObject:Move()
  	self.posX=self.posX+1
  	self.posY=self.posY+1
  	print(self.posX)
  	print(self.posY)
   end
  
  GameObject:SubClass("Player")
  
  function Player:Move()
    	self.base.Move(self)
  end
  
  local p1 = Player:new()
  print(p1)
  p1:Move()
  
  local p2 = Player:new()
  print(p2)
  p2:Move()