PygameSprites即使使用函数设置参数也会离开屏幕n

Question

所以我有一个防止精灵离开屏幕的功能，就是：`

def move_extent(self, x, y):
    if self.rect.right > 700:
      self.rect.right = 700
    elif self.rect.left < 0:
      self.rect.left = 0
    elif self.rect.y < 275:
      self.rect.y = 275
    elif self.rect.y > 275:
      self.rect.y = 275`

它可以防止精灵越过x坐标系，大部分情况下是y坐标系。但是，如果精灵位于最左侧或最右侧（0或700 x），它仍然会向上或向下移动

以下是主要的游戏循环：

while not done:

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

    keys = pygame.key.get_pressed()
    if keys[pygame.K_a]:
      protag.moveLeft(3)
    if keys[pygame.K_d]:
      protag.moveRight(3)
    if keys[pygame.K_w]:
      protag.moveUp(3)
    if keys[pygame.K_s]:
      protag.moveDown(3)


    all_sprites_list.update()

    screen.blit(background, (0, 0))

    all_sprites_list.draw(screen)
    move_extent(protag, x_coord, y_coord)

    pygame.display.flip()

    clock.tick(60)

pygame.quit()

Answer 1

几乎：）将测试更改为：

def move_extent(self, x, y):  # x and y are never used?
    if self.rect.right > 700:
        self.rect.right = 700

    if self.rect.left < 0:
        self.rect.left = 0

    if self.rect.y < 275:   # why y twice? this will limit y to be 275
        self.rect.y = 275   # and x is never checked ...

    if self.rect.y > 275:   # why y twice? this will limit y to be 275
        self.rect.y = 275`

目前，您先前的if已被使用，所有其他测试将不再进行测试

您可以将其缩短为：

def move_extent(self, x, y): 
    self.rect.right = min(700,self.rect.right) # take whatever is lower
    self.rect.left  = max(  0, self.rect.left) # take whatever is higher 
    self.rect.y = 275                          # fix y at 275

https://docs.python.org/3/library/functions.html#maxhttps://docs.python.org/3/library/functions.html#min