如何在不等待循环结束的情况下同时运行相同的方法？

Question

如下面的代码所示，当用户点击窗口时，我有一个函数会产生一个圆圈的动画。我的问题是，要让另一个圆圈出现并在一个圆圈已经生成后移动，我必须等待前一个圆圈完成其移动循环。在降雪函数结束时一个圆圈完成其“i in range”循环后，我可以单击并生成另一个圆圈。我希望能够随时单击并让尽可能多的圆圈同时移动（我知道我在函数下的代码中将其限制为 10 次）。看来我需要同时多次运行同一个方法。

from graphics import*
from random import*


win = GraphWin("Graphics Practice", 500, 500)

colours = ["blue", "red", "orange", "purple", "green", "black", "brown", "yellow", "pink"]

def snowfall(randColour):
    point = win.getMouse()
    circle = Circle(point, 40)
    circle.draw(win)
    circle.setFill(colours[randColour])
    for i in range(1000):
        circle.move(0, 1)
        time.sleep(0.002)

randColour = randint(0, 8)
for i in range (10):
    repeatColour = randColour
    snowfall(randColour)
    randColour = randint(0, 8)
    while randColour == repeatColour:
        randColour = randint(0, 8)

win.getMouse()
win.close()

我在多线程方面的一次失败尝试：

from graphics import*
from random import*


win = GraphWin("Graphics Practice", 500, 500)

colours = ["blue", "red", "orange", "purple", "green", "black", "brown", "yellow", "pink"]

def snowfall(randColour):
    point = win.getMouse()
    circle = Circle(point, 40)
    circle.draw(win)
    circle.setFill(colours[randColour])
    for i in range(1000):
        circle.move(0, 1)
        time.sleep(0.002)

randColour = randint(0, 8)
t1 = threading.Thread(target = snowfall, args = randColour)
for i in range (10):
    repeatColour = randColour
    t1.start()
    t1.join()
    randColour = randint(0, 8)
    while randColour == repeatColour:
        randColour = randint(0, 8)

win.getMouse()
win.close()

最新代码：

from graphics import*
from random import*


win = GraphWin("Graphics Practice", 500, 500)

colours = ["blue", "red", "orange", "purple", "green", "black", "brown", "yellow", "pink"]

class Snowflake(object):
    def __init__(self, randColour):
        self.circle = Circle(point, 40)
        self.circle.draw(win)
        self.circle.setFill(colours[randColour])

    def next_frame(self):
        self.circle.move(0, 1)

randColour = randint(0, 8)
sprites = []    
for i in range (100):
    repeatColour = randColour
    point = win.getMouse()
    sprites.append(Snowflake(randColour))
    randColour = randint(0, 8)
    while randColour == repeatColour:
        randColour = randint(0, 8)
    for s in sprites:
        while True:
            s.next_frame()
            time.sleep(0.02)
    win.getMouse()
    randColour = randint(0, 8)
    sprites.append(Snowflake(randColour, point))

win.getMouse()
win.close()

Answer 1

一个问题是您在启动后立即尝试join 线程t1。 join 一个线程是等待它完成，所以不是启动十个线程，而是启动然后等待一个线程十次。

但是，线程在这里是错误的方法。大多数图形包不允许多个线程绘制到相同的图形上下文，这是出于性能和流动性的充分考虑。这意味着您需要将绘图线程“从里到外”，将每个动画对象的状态放在一个“精灵”中，以便每个动画对象的状态都在它自己的实例中。然后，不是为每个精灵使用单独的线程，而是遍历所有精灵并在一个循环中更新它们，如下所示。

（请注意，我介绍了win.checkMouse()，它对鼠标事件进行非阻塞检查，因此允许您每次点击添加一个精灵，我相信这是您的意图。）

from graphics import *
from random import *

win = GraphWin("Graphics Practice", 500, 500)

colours = ["blue", "red", "orange", "purple", "green", "black", "brown", "yellow", "pink"]

class Snowflake(object):
    def __init__(self, randColour, point):
        self.circle = Circle(point, 40)
        self.circle.draw(win)
        self.circle.setFill(colours[randColour])

    def next_frame(self):
        self.circle.move(0, 1)

randColour = randint(0, 8)
sprites = []
for i in range(100):
    point = win.checkMouse()
    if point:
        randColour = randint(0, 8)
        sprites.append(Snowflake(randColour, point))
    for s in sprites:
        s.next_frame()
    time.sleep(0.1)
win.close()