–– coding: utf-8 ––
@Time : 2018/7/30 15:39
@Author : G.Hope
@Email : 1638327522@qq.com
@File : ballGame.py
@Software: PyCharm

通过键盘方向键控制小球移动方向，使其不触碰到程序窗口边界。否则认为游戏失败，程序自动退出。

import pygame


def draw_ball(place, color, pos):
    pygame.draw.circle(place, color, pos, 20)


# 方向对应的key值
Up = 273
Down = 274
Left = 276
Right = 275

if __name__ == '__main__':
    pygame.init()
    screen = pygame.display.set_mode((800, 600))
    screen.fill((255, 255, 255))

    pygame.display.flip()

    # 保存初始坐标
    ball_x = 400
    ball_y = 300
    x_speed = 1
    y_speed = 1

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

            if event.type == pygame.KEYDOWN:
                if event.key == Up:
                    x_speed = 0
                    y_speed = -1
                elif event.key == Down:
                    x_speed = 0
                    y_speed = 1
                elif event.key == Right:
                    x_speed = 1
                    y_speed = 0
                elif event.key == Left:
                    x_speed = -1
                    y_speed = 0
        # 刷新屏幕
        pygame.time.delay(10)
        screen.fill((255, 255, 255))
        ball_x += x_speed
        ball_y += y_speed
        if ball_x + 20 >= 800 or ball_x <= 20 or ball_y + 20 >= 600 or ball_y <= 20:
            print('游戏结束')
            exit()
            # ball_x = 600 - 20
            # x_speed *= -1

        # if ball_x <0:
        #     ball_x = 0
        #     x_speed *= -1
        draw_ball(screen, (255, 0, 0), (ball_x, ball_y))

        pygame.display.update()