为什么我的表面似乎已经正确放置了

Question

我是Python的新手，并且正在关注一个名为“ Pygame的最终介绍”的YouTube视频。我已经有一切正常，我只是打开文件以开始添加更多代码，而我的屏幕不再填充。它应该显示的是一个天空，地面，一个小太空人和一个从左到右移动的蜗牛。似乎正在放置表面，因为我仍然可以在屏幕上与它们互动并获得打印语句，但它只是黑色。

这是代码，我不确定如何开始对此进行故障排除，因为我没有得到追溯或任何东西。从技术上讲，一切都在起作用。

import pygame
from sys import exit

pygame.init()
screen = pygame.display.set_mode((800, 400))
pygame.display.set_caption("Runner")
clock = pygame.time.Clock()
test_font = pygame.font.Font("font/pixeltype.ttf", 75)

sky_surface = pygame.image.load('graphics/sky.png').convert_alpha()
ground_surface = pygame.image.load('graphics/ground.png').convert_alpha()
score_surface = test_font.render("Runnin' Round!", False, (64, 64, 64))
score_rect = score_surface.get_rect(midtop=(400, 50))


snail_surface = pygame.image.load("graphics/snail/snail1.png").convert_alpha()
snail_rect = snail_surface.get_rect(bottomright=(600, 300))
player_surface = pygame.image.load("graphics/player/player_walk_1.png").convert_alpha()
player_rect = player_surface.get_rect(topleft=(80, 200))

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()
        # if event.type == pygame.MOUSEMOTION:
        #    if player_rect.collidepoint(event.pos): print("collision") #works with black screen??

    screen.blit(sky_surface, (0, 0))  # place sky
    screen.blit(ground_surface, (0, 300))  # place ground
    pygame.draw.rect(screen, '#c0e8ec', score_rect)
    pygame.draw.rect(screen, '#c0e8ec', score_rect, 10)
    screen.blit(score_surface, score_rect)
    print('placed background') #test to see if above is broke

    snail_rect.x -= 5
    if snail_rect.right <= 0:
        snail_rect.left = 800
    screen.blit(snail_surface, snail_rect)  # place snail
    screen.blit(player_surface, player_rect)  # place player

    if player_rect.colliderect(snail_rect):
        print("colission") #also works with black screen???

    mouse_pos = pygame.mouse.get_pos()
    if player_rect.collidepoint(mouse_pos):
        pygame.mouse.get_pressed()
        print(pygame.mouse.get_pressed()) #this works even with black screen????

    clock.tick(60)

Answer 1

在clock.tick之前或之后，
type pygame.display.update（）
您没有更新显示，所以它是黑色的