12作 pygame知识

import pygame

if __name__ == '__main__':

    pygame.init()
    window = pygame.display.set_mode((400, 600))
    window.fill((255, 255, 255))
    pygame.display.flip()

    x = 100
    y = 100
    r = 50

    y_speed = 2
    x_speed = 2

    while True:

        pygame.time.delay(10)

        window.fill((255, 255, 255))

        pygame.draw.circle(window, (255, 0, 0), (x, y), r)
        pygame.display.update()

        y += y_speed
        x += x_speed

        if y > 600 - r:
            y = 600 - r
            y_speed = -4

        elif y<50:
            y = 50
            y_speed = 2

        elif x > 400 - r:
            x = 400 - r
            x_speed = -4

        elif x < 50:
             x = 50
             x_speed = 2

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