为什么pygame中的群组列表必须具有“更新"功能?功能，还有其他功能吗? [英] Why do group lists in pygame have to have "update" functions, and not any other?

问题描述

我做了一个小颗粒的应用程序，但是我正在测试它，并且底部的功能必须称为更新".我认为函数名称就像变量一样，只是一个名称.我以为它的名字无关紧要，只要您调用它的名字是一样的即可.显然我错了.它将仅识别更新".如果我将功能更改为"move"，它将引发错误.有人可以解释为什么会这样吗?

I made a small particles application, but I was testing it and the function at the bottom has to be called "update". I thought the function name, just like variables, was just a name. I thought it didn't matter what it was named, as long as it's the same when you call it. Apparently I was wrong. It will only recognize "update". If I change the function to "move", it will throw an error. Could someone explain why it's like this?

import pygame
import random
pygame.init()
win_height=600
win_width=800
win=pygame.display.set_mode((win_width,win_height))
pygame.display.set_caption("List practice")
white=(255,255,255)
black=(0,0,0)
clock=pygame.time.Clock()

class particle_class(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image=pygame.Surface((25,25))
        self.image.fill(white)
        self.rect=self.image.get_rect()
        self.speed=0
    def update(self):
        self.rect.y+=self.speed
        
particles=pygame.sprite.Group()

for i in range(10):
    particle=particle_class()
    particle.speed=random.randrange(5,11)
    particle.rect.y=0
    particle.rect.x=random.randrange(0,win_width+1)
    particles.add(particle)

while True:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            pygame.quit()
    win.fill(black)
    particles.update()
    particles.draw(win)
    pygame.display.update()
    for particle in particles:
        if particle.rect.y>win_height:
            particle.rect.y=0
            particle.speed=random.randrange(5,11)
            particle.rect.x=random.randrange(0,win_width+1)

推荐答案

它将仅识别更新".如果我将功能更改为"move"，则会引发错误.

It will only recognize "update". If I change the function to "move", it will throw an error.

是的.阅读 pygame.sprite.Group .

Yes of course. Read the documentation of pygame.sprite.Group.

pygame.sprite.Group.update() 和 pygame.sprite.Group.draw() 是 pygame.sprite.Group 提供的方法.
前者将委托给所包含的

pygame.sprite.Group.update() and pygame.sprite.Group.draw() are methods which are provided by pygame.sprite.Group.
The former delegates the to the update method of the contained pygame.sprite.Sprites - you have to implement the method.

pygame.sprite.Group.update()

在组中的所有Sprite上调用update()方法.

Calls the update() method on all Sprites in the Group.

稍后，它们使用所包含的 pygame.sprite.Sprite 的 image 和 rect 属性绘制对象-您必须确保 pygame.sprite.Sprite 具有必需的属性

The later uses the image and rect attributes of the contained pygame.sprite.Sprites to draw the objects - you have to ensure that the pygame.sprite.Sprites have the required attributes

pygame.sprite.Group.draw()

将包含的Sprite绘制到Surface参数.这会将Sprite.image属性用作源表面，并将Sprite.rect属性用作位置.

Draws the contained Sprites to the Surface argument. This uses the Sprite.image attribute for the source surface, and Sprite.rect for the position.

---

如果要使用自己的方法使用类似的机制，则必须实现从 pygame.sprite.Group 派生的自己的类.例如:

---

If you want a similar mechanism with your own method, then you have to implement your own class derived from pygame.sprite.Group. For instance:

class MyGroup(pygame.sprite.Group):

    def __init__(self, *args):
        super().__init__(*args) 

    def move(self):
        for sprite in self:
            sprite.move()

class particle_class(pygame.sprite.Sprite):
    # [...]

    def move(self):
        self.rect.y+=self.speed

particles = MyGroup()

for i in range(10):
    particle=particle_class()
    particle.speed=random.randrange(5,11)
    particle.rect.y=0
    particle.rect.x=random.randrange(0,win_width+1)
    particles.add(particle)

particles.move()

这篇关于为什么pygame中的群组列表必须具有“更新"功能?功能，还有其他功能吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！