Question

我试图在我的pygame项目中使用多态，但我一直在收到错误。

我有一个Moveable类和一个继承自Moveable的Objects类，我得到一个AttributeError：＆＃39; NoneType＆＃39;对象没有属性＆＃39; ypos＆＃39;在我的游戏循环中。

我计划在我的项目中拥有更多可移动的物体，比如人，房屋，道路标志......如果我可以使用它。

class Moveable:
    __name = ""
    __xpos = 0
    __ypos = 0
    __hight = 0
    __width = 0
    __speed = 0
    __image = 0

    def __init__(self, xpos, ypos, hight, width, speed, image):
        self.__xpos = xpos
        self.__ypos = ypos
        self.__hight = hight
        self.__width = width
        self.__image = image

    def set_xpos(self, xpos):
        self.__xpos = xpos

    def get_xpos(self):
        return self.__xpos

    # ... and all my other getters and setters...


class Objects(Moveable):

    def car(xpos, ypos, width, hight, speed, image):
        pygame.Surface.blit(gameDisplay, image, [xpos, ypos, hight, width])

def game_loop():

game_exit = False #sets the game loop to false

while not game_exit: # runs the game loop until the game exit = true

    car = Objects.car(random.randrange(250, 550), -400, 60, 70, 4, pygame.image.load('car.png'))
    gameDisplay.blit(backGroundImg, (0, 0)) #displays the background
    car.ypos += car.speed # the error is here **********

[R

Answer 1

如果这是你的意图，你需要返回pygame。

def car(xpos, ypos, width, hight, speed, image):
    return pygame.Surface.blit(gameDisplay, image, [xpos, ypos, hight, width])

目前，car没有return语句，因此为方法分配变量将返回None，因此您尝试访问NoneType

Python：尝试将多态性与pygame一起使用

1 个答案: