矩形未在屏幕上绘制

Question

下面的代码是创建一个按钮，当光标悬停在它上面时它会改变颜色，同时结束程序，如果它被点击。结果不显示按钮，只显示背景。我在底部有执行后 pygame 窗口的图像。'''# initialisingimport pygame, syspygame.init()HEIGHT = 720WIDTH  = 720screen = pygame.display.set_mode((HEIGHT,WIDTH))# colour WHITE  = (255,255,255)BLACK  = (0,  0  ,0  )MAROON = (128,0  ,0  )RED    = (255,0  ,0  )x, y = pygame.mouse.get_pos()# rendering a text written in # this font # defining a font smallfont = pygame.font.SysFont('Corbel',35) text = smallfont.render('quit' , True , BLACK)         # superimposing the text onto our button screen.blit(text,(WIDTH/2 +50, HEIGHT/2)) # describing the processwhile True:    for ev in pygame.event.get():                if ev.type == pygame.QUIT:            pygame.quit()        #describing events        if ev.type == pygame.MOUSEBUTTONDOWN:                        if WIDTH/2 -70 <= x <= WIDTH/2 + 70 and HEIGHT/2 -70 <= x <= HEIGHT/2 + 70:                pygame.quit()                pygame.display.flip()            if  WIDTH/2 -70 <= x <= WIDTH/2 + 70 and HEIGHT/2 -70 <= x <= HEIGHT/2 + 70:        pygame.draw.rect(screen,RED,(100,100,500,500))     else:        pygame.draw.rect(screen,MAROON,(100,100,500,500))                      # filling screen with colour    screen.fill(WHITE)         # updates the frames of the game     pygame.display.update()         我试过 pygame.display.flip()，改变矩形的位置，但问题没有解决。我是 pygame 的初学者，因此才刚刚开始。

Answer 1

您必须先绘制矩形screen.fill(WHITE)。注意pygame.Surface.fill用纯色填充整个表面。之前绘制的所有内容都被覆盖了。

# describing the process

while True:

    # [...]

    # filling screen with colour

    screen.fill(WHITE)

    if  WIDTH/2 -70 <= x <= WIDTH/2 + 70 and HEIGHT/2 -70 <= x <= HEIGHT/2 + 70:

        pygame.draw.rect(screen,RED,(100,100,500,500)) 

    else:

        pygame.draw.rect(screen,MAROON,(100,100,500,500))

    

    # updates the frames of the game 

    pygame.display.update()