Question

所以，我已经开始在Youtube上从新闻波士顿学习PyGame了，我有点卡在boundaries video上。

在视频中，在1:50，他输入：

if lead_x > display_width or lead_x < 0 or lead_y > display_height or lead_y < 0:
        gameExit = True

这将游戏的边界设置为显示。蛇越过它之后游戏退出。但是，当我做同样的事情时，它似乎对我的程序没有影响。蛇继续前进而没有结束节目。有什么我做错了吗？源代码如下。谢谢！

import pygame

pygame.init()

display_width = 800
display_height = 600

gameDisplay = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption('Snake')

white = (255,255,255)
black = (0,0,0)
red = (255,0,0)

pygame.display.update()

gameExit = False

lead_x = 300
lead_y = 300
lead_x_change = 0
lead_y_change = 0

clock = pygame.time.Clock()

while not gameExit:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            gameExit = True
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                lead_x_change = -10
                lead_y_change = 0
            elif event.key == pygame.K_RIGHT:
                lead_x_change = 10
                lead_y_change = 0
            elif event.key == pygame.K_UP:
                lead_y_change = -10
                lead_x_change  = 0
            elif event.key == pygame.K_DOWN:
                lead_y_change = 10
                lead_x_change = 0
    if lead_x > display_width or lead_x < 0 or lead_y > display_height or lead_y < 0:
        gameExit = True

    lead_x += lead_x_change
    lead_y += lead_y_change
    gameDisplay.fill(white)
    pygame.draw.rect(gameDisplay, black, [lead_x,lead_y,10,10])
    pygame.display.update()
    clock.tick(15)

pygame.quit()
quit()

Answer 1

实际上在用pygame测试你的代码之后，似乎工作正常。然而角色确实离开了屏幕。下面的代码将阻止角色离开屏幕。

您需要检查lead_x＆amp; lead_y已添加到已移动的金额（例如lead_x + lead_x_changed）改变线：

if (lead_x + lead_x_change) > display_width or (lead_x + lead_x_change) < 0 or (lead_y + lead_y_change) > display_height or (lead_y + lead_y_change) < 0:

完整示例：

lead_x = 300
lead_y = 300
lead_x_change = 0
lead_y_change = 0

clock = pygame.time.Clock()
gameExit = False

while not gameExit:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            gameExit = True
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                lead_x_change = -10
                lead_y_change = 0
            elif event.key == pygame.K_RIGHT:
                lead_x_change = 10
                lead_y_change = 0
            elif event.key == pygame.K_UP:
                lead_y_change = -10
                lead_x_change  = 0
            elif event.key == pygame.K_DOWN:
                lead_y_change = 10
                lead_x_change = 0


    lead_x += lead_x_change
    lead_y += lead_y_change
    gameDisplay.fill(white)
    pygame.draw.rect(gameDisplay, black, [lead_x,lead_y,10,10])
    pygame.display.update()
    clock.tick(15)
    if (lead_x + lead_x_change) > display_width or (lead_x + lead_x_change) < 0 or (lead_y + lead_y_change) > display_height or (lead_y + lead_y_change) < 0:
        gameExit = True

pygame.quit()
quit()

Pygame边界问题

1 个答案: