lua面向对象---调用基类函数

Shape = {}

Shape.__index = Shape

function Shape:create(x, y)
	local s = {}
	setmetatable(s, self)
        s:__init(x, y)
	return s
end
function Shape:__init(x,y)
    self.x = x
    self.y = y
end
function Shape:setXY(x,y)
	self.x = x
	self.y = y
    self:draw()
end
function Shape:draw()
    print("Shape:draw() x="..self.x.." y="..self.y)
end

Rect = Shape:create(0, 0)

Rect.__index = Rect

Rect.__super = Shape
function Rect:create(x,y,w,h)
    local r = {}
    setmetatable(r, self)
    r:__init(x,y,w,h)
    return r
end
function Rect:__init(x,y,w,h)
    self.__super.__init(self,x,y)
    self.w = w
    self.h = h
end
function Rect:draw()
    self.__super.draw(self)
    print("Rect:draw() w="..self.w.." h="..self.h)
end

s = Shape:create(9,8)
s:draw()

r = Rect:create(1,2,3,4)
r:draw()

r:setXY(5,6)