python - Python 中的循环

Question

我正在尝试让 pygame 中的 Sprite throw 手榴弹。我希望它向前移动一点，然后停止。我的问题是让手榴弹顺利前进。以下代码的作用是让它立即移动到兴趣点，而不是平滑移动。

[手榴弹类]

#Grenade Class
class Explosive(pygame.sprite.Sprite):
    def __init__(self, location):
        pygame.sprite.Sprite.__init__(self)
        self.pos = location
        self.image = Nade
        self.rect = self.image.get_rect()
        self.rect.right = self.image.get_rect().right
        self.rect.left = self.image.get_rect().left
        self.rect.top = self.image.get_rect().top
        self.rect.bottom = self.image.get_rect().bottom
        self.rect.center = location
    def move(self):
        if Player.direction == 0:
            self.rect.centery = self.rect.centery - 5
        if Player.direction == 180:
                self.rect.centery = self.rect.centery + 5
        if Player.direction == 90:
            self.rect.centerx = self.rect.centerx + 5
        if Player.direction == 270:
            self.rect.centerx = self.rect.centerx - 5 

[扔手榴弹(在主循环中)]

if event.key == pygame.K_e and grenadeNum > 0:
            Grenade = Explosive([Player.rect.centerx, Player.rect.centery])
            for i in range(1, 10)
                Grenade.move()

Answer 1

虽然您确实需要更新显示，但还有第二个问题。现在，你根本没有告诉它等待，所以它会立即完成所有十个 Action 。这将同样突然，因此您可能需要导入时间并在其中的某个位置添加 time.sleep() 。因为在一个独立的“for”循环中移动手榴弹，如果你还有其他事情发生，这将会停止。如果你有一个 while 循环来管理一切，请对手榴弹调用“更新”函数，它们将有计数器来知道它们是否应该在本轮中移动。如果其他 Sprite 需要做某事，您也可以调用它们的方法。最后，为了加快程序速度，您只能更新 Sprite 移动的部分的屏幕。当您将所有这些放在一起时，它是这样的:

import time

grenades = pygame.sprite.RenderUpdates()        #initializes a pygame group for sprites

class Explosive(pygame.sprite.Sprite):
def __init__(self, location):
    pygame.sprite.Sprite.__init__(self)
    self.pos = location
    self.image = Nade
    self.rect = self.image.get_rect()
    self.rect.right = self.image.get_rect().right
    self.rect.left = self.image.get_rect().left
    self.rect.top = self.image.get_rect().top
    self.rect.bottom = self.image.get_rect().bottom
    self.rect.center = location
    self.move_counter = 10               #adds a counter for how many rounds left of moving the grenade has
def update(self):
    if self.move_counter > 0:            #checks that self still has turns left to move
        <insert screen variable name>.fill(<insert background color>,self.rect)    #erases self in old location
        if Player.direction == 0:
            self.rect.centery = self.rect.centery - 5
        if Player.direction == 180:
                self.rect.centery = self.rect.centery + 5
        if Player.direction == 90:
            self.rect.centerx = self.rect.centerx + 5
        if Player.direction == 270:
            self.rect.centerx = self.rect.centerx - 5
        pygame.display.update(self.draw((screen)))    #draws self in new location
        self.move_counter -= 1           #subtracts one from the counter to mark that another turn of moving has passed by

while True:
    grenades.update()
    #anything else you want to do in real time here
    time.sleep(0.1)