TypeError 在 Pygame 中在后台 blit 代码中创建

Question

我正在尝试将背景图像 blit 到屏幕上，但是，我似乎一直运行陷入这个错误：

TypeError: unbound method update() must be called with Background instance as first argument (got nothing instead)

错误消息指向这行代码：

Background.update()

我试过在 class 的外部和内部移动 blit，但不断出现相同的错误消息。我的猜测是这也会影响船舶代码。

这是整个 py 文件：

import pygame
from pygame.locals import *

# Colors
RED     = (255,0,0)
GREEN   = (0,255,0)
BLUE    = (0,0,255)

# Screen Size
SCREEN_X = 400
SCREEN_Y = 400

# Loading Images
background = pygame.image.load('StarBackground.png')
powership = pygame.image.load('PowerShip.png')

class Ship(pygame.sprite.Sprite):

    # Movement rate of change
    change_x = 0
    change_y = 0

    # Methods
    def __init__(self):

        # Starts the parent's constructor
        pygame.sprite.Sprite.__init__(self)

        # Sets the ship's image
        self.image = powership

        # Sets the ship's rect
        self.rect = self.image.get_rect()

        # Set the ship's start location
        self.rect.x = 0
        self.rect.y = 0

    def move_right(self):
        self.change_x = 1

    def move_left(self):
        self.change_x = 1

    def move_up(self):
        self.change_y = 1

    def move_down(self):
        self.change_y = 1

    def stop_x(self):
        self.change_x = 0

    def stop_y(self):
        self.change_y = 0

    def update(self, screen):
        self.rect.x += self.change_x
        self.rect.y += self.change_y

        screen.blit(self.image,self.rect)

class Background(pygame.sprite.Sprite):

    def __init__(self):

        # Starts the parent's constructor
        pygame.sprite.Sprite.__init__(self)

        # Sets the ship's image
        self.image = background

        # Sets the ship's rect
        self.rect = self.image.get_rect()

        # Sets the background's starting location
        self.rect.x = 0
        self.rect.y = 0

    def update(self, screen):

        screen.blit(self.image,self.rect)

def main():
    pygame.init()

    # Set the height and width of the screen
    size = [SCREEN_X, SCREEN_Y]
    screen = pygame.display.set_mode(size)

    pygame.display.set_caption("Space Adventure")

    # Creating the game objects
    background = Background()
    ship = Ship()

    # Close button exit code
    finished = False

    # Manages the frames per second
    clock = pygame.time.Clock()

    # Game loop
    while not finished:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                finished = True

            keyboardInput = pygame.key.get_pressed()

            if event.type == pygame.KEYDOWN:
                if keyboardInput[K_RIGHT]:
                    ship.move_right()
                if keyboardInput[K_LEFT]:
                    ship.move_left()
                if keyboardInput[K_UP]:
                    ship.move_up()
                if keyboardInput[K_DOWN]:
                    ship.move_down()

            if event.type == pygame.KEYUP:
                if keyboardInput[K_RIGHT]:
                    ship.stop_x()
                if keyboardInput[K_LEFT]:
                    ship.stop_x()
                if keyboardInput[K_UP]:
                    ship.stop_y()
                if keyboardInput[K_DOWN]:
                    ship.stop_y()

            clock.tick(60)
            pygame.display.flip()
            Background.update()
            Ship.update()

    pygame.quit()

if __name__ == "__main__":
    main()

编辑：将更新代码更改为以下修复了问题：

Background.update(screen)
Ship.update(screen)

Answer 1

这正是消息所说的：

TypeError: unbound method update() must be called with Background instance as first argument (got nothing instead)

这意味着您正在调用类而不是实例（对象）。在 python 中，模块是大写的，按照惯例，实例不应该大写。

未大写的行应如下所示：

background.update(screen)
ship.update(screen)

TypeError 在 Pygame 中在后台 blit 代码中创建

TypeError created in Pygame within background blit code

python

pygame

python-3.6