无法逆向移动

Question

///////////////////////////// [solved]

Answer 1

您必须在每一帧中重新绘制场景。您必须在应用程序循环中进行绘图。典型的 PyGame 应用程序循环必须：

• 使用pygame.time.Clock.tick 限制每秒帧数以限制 CPU 使用率
• 通过调用pygame.event.pump() 或pygame.event.get() 来处理事件。
• 根据输入事件和时间更新游戏状态和对象位置（分别为帧）
• 清除整个显示或绘制背景
• 绘制整个场景（blit所有对象）
• 调用pygame.display.update()或pygame.display.flip()更新显示

import pygame, sys
import random
from pygame.locals import *

pygame.init()
screen = pygame.display.set_mode((800, 800))
pygame.display.set_caption("board")
exit = False

grey = (224,224, 224)
green = (204, 255, 204)
blue = (204, 255, 255)
purple = (204, 204, 255)
black = (0, 0, 0)
white = (255, 255, 255)
rows = 10
cols = 14
colors = [grey, green, blue, purple]


def display_board(screen_width, screen_height, square_size, margin):
    counter_pos = [0, 0]
    direction = 'right'

    fields = []
    for row in range(rows):
        rect = pygame.Rect(margin, margin + row * (square_size + 2), square_size, square_size)
        fields.append((random.choice(colors), rect))
        rect = pygame.Rect(margin + (cols-1) * (square_size + 2), margin + row * (square_size + 2), square_size, square_size)
        fields.append(( random.choice(colors), rect))
    for col in range(1, cols-1):
        rect = pygame.Rect(margin + col * (square_size + 2), margin, square_size, square_size)
        fields.append((random.choice(colors), rect))
        rect = pygame.Rect(margin + col * (square_size + 2), margin + (rows-1) * (square_size + 2), square_size, square_size)
        fields.append(( random.choice(colors), rect))

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            elif event.type == pygame.MOUSEBUTTONDOWN:
                if direction == 'right':
                    counter_pos[0] += 1
                    if counter_pos[0] >= cols - 1:
                        direction = 'down'
                elif direction == 'down':
                    counter_pos[1] += 1
                    if counter_pos[1] >= rows - 1:
                        direction = 'left'
                elif direction == 'left':
                    counter_pos[0] -= 1
                    if counter_pos[0] <= 0:
                        direction = 'up'
                elif direction == 'up':
                    counter_pos[1] -= 1
                    if counter_pos[1] <= 0:
                        direction = 'right'

        screen.fill(0)
        for color, rect in fields:
            pygame.draw.rect(screen, color, rect)
        pygame.draw.rect(screen, (255, 255, 255), (margin + counter_pos[0] * (2 + square_size), margin + counter_pos[1] * (square_size + 2), square_size, square_size))
        pygame.display.update()

display_board(800, 600, 50, 20)