python pygame 错误：视频系统未初始化

Question

我遇到了这个错误，不太清楚怎么解决或者是什么原因导致的。问题似乎出现在这个注释下面。你可以看到，使用了 event.get 的这个 for 循环，似乎让视频系统无法正常初始化。

Traceback (most recent call last):
  File "E:\ICS\Assignment\Super Break\Super Break.py", line 49, in <module>
    main()
  File "E:\ICS\Assignment\Super Break\Super Break.py", line 26, in main
    for event in pygame.event.get():
error: video system not initialized

import pygame, pySprites
pygame.init()
pygame.mixer.init()
screen = pygame.display.set_mode((640, 480))

def main(): 
    pygame.display.set_caption("Super Break")

    background = pygame.Surface(screen.get_size()) 
    background = background.convert() 
    background.fill((255, 255, 255)) 
    screen.blit(background, (0, 0))

    score_keeper = pySprites.ScoreKeeper() 
    ball = pySprites.Ball(screen) 
    player1 = pySprites.Player(screen, 1)
    allSprites = pygame.sprite.Group(score_keeper,ball, player1)

    clock = pygame.time.Clock() 
    keepGoing = True

    pygame.mouse.set_visible(False)

    while keepGoing:
        clock.tick(30)
        for event in pygame.event.get():
            if event.type == pygame.QUIT: 
                keepGoing = False
            elif event.type == pygame.JOYHATMOTION: 
                player1.change_direction(event.value) 
            elif event.type == pygame.KEYDOWN: 
                if event.key == pygame.K_UP: 
                    player2.change_direction((0, 1)) 
                if event.key == pygame.K_DOWN: 
                    player2.change_direction((0, -1))


            allSprites.clear(screen, background) 
            allSprites.update() 
            allSprites.draw(screen)        
            pygame.display.flip()            

            # def speed_up(self): 
            #    if self.__dx > 0: 
            #       self.__dx += 1

        pygame.mouse.set_visible(True)
        pygame.quit()
main()

Answer 1

你的缩进有问题。你在主循环里调用了 pygame.quit，这会导致视频屏幕被关闭，从而出现上面的错误。我还注意到你在事件循环里调用了绘图函数。它们应该在主循环里被调用。

这是修正后的代码：

import pygame, pySprites
pygame.init()
pygame.mixer.init()
screen = pygame.display.set_mode((640, 480))

def main(): 
    pygame.display.set_caption("Super Break")

    background = pygame.Surface(screen.get_size()) 
    background = background.convert() 
    background.fill((255, 255, 255)) 
    screen.blit(background, (0, 0))

    score_keeper = pySprites.ScoreKeeper() 
    ball = pySprites.Ball(screen) 
    player1 = pySprites.Player(screen, 1)
    allSprites = pygame.sprite.Group(score_keeper,ball, player1)

    clock = pygame.time.Clock() 
    keepGoing = True

    pygame.mouse.set_visible(False)

    while keepGoing:
        clock.tick(30)
        for event in pygame.event.get():
            if event.type == pygame.QUIT: 
                keepGoing = False
            elif event.type == pygame.JOYHATMOTION: 
                player1.change_direction(event.value) 
            elif event.type == pygame.KEYDOWN: 
                if event.key == pygame.K_UP: 
                    player2.change_direction((0, 1)) 
                if event.key == pygame.K_DOWN: 
                    player2.change_direction((0, -1))


        allSprites.clear(screen, background) 
        allSprites.update() 
        allSprites.draw(screen)        
        pygame.display.flip()            

    pygame.mouse.set_visible(True)
    pygame.quit()
main()