为什么多线程函数没有在计时器之前运行

Question

我正在尝试使用多线程来显示一个加载轮，同时进行一些后台计算。我尝试启动多线程函数，然后运行计时器来模拟计算。问题是，当计时器结束时，线程首先开始运行，即使我首先启动线程。。。

from tkinter import *
from tkinter import messagebox
import time
from threading import *
from PIL import Image, ImageTk
# Create Object
root = Tk()

# Set geometry
root.geometry("400x400")
flag = True
# use threading
def threading():
t1=Thread(target=work)
t1.start()
time.sleep(10)
# work function
def work():
print("sleep time start")
image = Image.open("Static/spinner0.png")
img = ImageTk.PhotoImage(image)
lab = Label(root,image=img)
lab.pack()
while flag:
for i in range(8):
image = Image.open("Static/spinner"+str(i)+".png")
img = ImageTk.PhotoImage(image)
lab['image'] = img
time.sleep(0.2)
#return False
print("sleep time stop")
def on_closing():
if messagebox.askokcancel("Quit", "Do you want to quit?"):
flag = False
root.destroy()

# Create Button
Button(root,text="Click Me",command = threading).pack()
# Execute Tkinter
root.protocol("WM_DELETE_WINDOW", on_closing)
root.mainloop()

Answer 1

只是把答案放在这里，以避免人们为解决方案挖掘评论。

一种方法是让计算和更新函数在额外的不同线程上运行，这样主进程事件循环就不会中断，并且您可以调用time.sleep，只要它不发生在主线程中，这就很好。

python中的一个线程消耗的内存低于100KB(加上运行在其上的代码中的变量的内存(，所以让多个线程运行是可以的。

from tkinter import *
from tkinter import messagebox
import time
from threading import *
from PIL import Image, ImageTk
# Create Object
root = Tk()
# Set geometry
root.geometry("400x400")
flag = True

# use threading
def threading():
t1 = Thread(target=work)
t1.start()
t2 = Thread(target=time.sleep,args=(10,)) # the heavy computation function.
t2.start()
# control is given back to the main event loop
# work function
def work():
print("sleep time start")
image = Image.open("Static/spinner0.png")
img = ImageTk.PhotoImage(image)
lab = Label(root,image=img)
lab.pack()
while flag:
for i in range(8):
image = Image.open("Static/spinner"+str(i)+".png")
img = ImageTk.PhotoImage(image)
lab['image'] = img
time.sleep(0.2)
#return False
print("sleep time stop")

def on_closing():
if messagebox.askokcancel("Quit", "Do you want to quit?"):
flag = False
root.destroy()

# Create Button
Button(root, text="Click Me", command=threading).pack()
# Execute Tkinter
root.protocol("WM_DELETE_WINDOW", on_closing)
root.mainloop()