Pygame sprite创建重复而不是移动

Posted 2021-04-18

我对Pygame很新。

我试图使用Pygame在Python中重新创建Pong，但我遇到了障碍。

这是我的代码：

import pygame

pygame.init()
UP = "up"
DOWN = "down"
white = (255,255,255)
black = (0,0,0)
pygame.mouse.set_visible(True)

resolution = (800,600)
window = pygame.display.set_mode(resolution)
pygame.display.set_caption("Pong!")
clock = pygame.time.Clock()


sprites_list = pygame.sprite.Group()


running = True


class Paddle(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()

        self.image = pygame.Surface((25,100))
        self.image.fill(white)

        pygame.draw.rect(self.image,white, (0,0,25,100))

        self.rect = self.image.get_rect()

    def move(self,direction,pixels):
        if direction == DOWN:
            self.rect.y -= pixels
        if direction == UP:
            self.rect.y += pixels

player1 = Paddle()

player1.rect.x = 0
player1.rect.y = 200



sprites_list.add(player1)

while running:


    for event in pygame.event.get():

        if event.type == pygame.QUIT:
            running = False

    keys = pygame.key.get_pressed()
    if keys[pygame.K_DOWN]:
        player1.move(DOWN, 5)
    if keys[pygame.K_UP]:
        player1.move(UP, 5)

    sprites_list.update()

    sprites_list.draw(window)


    pygame.display.flip()
    clock.tick(60)

pygame.quit()

我试图让player1，一个Paddle对象，根据按下哪个键向上或向下移动。当我运行此代码时，在按下向上或向下箭头后，player1伸出;将5个像素添加到player1.rect上。

我做错了什么，为什么sprites_list.update（）不会将player1置于新的位置？

答案

在新循环中绘制元素之前，必须清除屏幕。 您可以用黑色window.fill((0,0,0))填充窗口或在每个循环中绘制背景图像。

这是重组后添加window.fill(BLACK)的代码

import pygame

# --- constants --- (UPPER_CASE_NAMES)

WHITE = (255, 255, 255)
BLACK = (0, 0, 0)

UP = "up"
DOWN = "down"

SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600

# --- classes ---- (CamelCaseNames)

class Paddle(pygame.sprite.Sprite):

    def __init__(self):
        super().__init__()

        self.image = pygame.Surface((25,100))
        self.image.fill(WHITE)

        # you don't have to draw white rect if all surface already is white
        #pygame.draw.rect(self.image,white, (0,0,25,100))

        self.rect = self.image.get_rect()

    def move(self, direction, pixels):
        if direction == DOWN:
            self.rect.y += pixels
        if direction == UP:
            self.rect.y -= pixels

# --- functions --- (lower_case_names)

# empty

# --- main --- (lower_case_names)

# - init -

pygame.init()
pygame.mouse.set_visible(True)
window = pygame.display.set_mode(resolution)
pygame.display.set_caption("Pong!")

# - objects -

sprites_list = pygame.sprite.Group()

player1 = Paddle()
player1.rect.x = 0
player1.rect.y = 200

sprites_list.add(player1)

# - mainloop -

clock = pygame.time.Clock()

running = True

while running:

    # - events -

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    keys = pygame.key.get_pressed()

    if keys[pygame.K_DOWN]:
        player1.move(DOWN, 5)
    if keys[pygame.K_UP]:
        player1.move(UP, 5)

    # - updates (without draws) -

    sprites_list.update()

    # - draws (without updates) -

    window.fill(BLACK) # <--- clear screen 

    sprites_list.draw(window)

    pygame.display.flip()
    clock.tick(60)

# - end -

pygame.quit()