multithreading - tkinter 线程通信

Question

我有代码应该显示 tkinter 小部件(注意:尚未实现)和另一个线程之间的通信。作为这两者之间的通信，我选择 python 队列。要查看真正发生的事情，控制台中会显示打印，这不是我所期望的。

正如在 generate_text 输出的 process sleep 时间后的控制台输出中可以看到的那样。我期望的是，由于 generate_text 比 process 慢，我会看到更多的 process is called 和 Item x ，但这并没有发生。

import tkinter as tk
import threading
import queue
import time

def generate_text(storage):
    count = 0
    while True:
        message = "Item {}".format(count)
        storage.put(message)
        print(message)

        count +=1

        time.sleep(3000/1000)

def process(storage):
    print("process is called")

    try:
        storage.get()
    except queue.Empty:
        print("queue empty")

    # register awake function
    root.after(500, process, message)

# init variables
message = queue.Queue()

root = tk.Tk()

t = threading.Thread(target=generate_text, args=(message,))
t.setDaemon(True)
t.start()

root.after(500, process, message)
root.mainloop()

输出:

Item 0
process is called
process is called
Item 1
process is called
Item 2
process is called
Item 3
process is called...

Desired output:
Item 0
process is called
process is called
process is called
process is called
process is called
process is called
Item 1

Answer 1

storage.get() 是一个阻塞函数。在队列中有一个项目之前，它不会到达 root.after(500, process, message) 调用。

您可以使用 storage.get_nowait() 或 storage.get(False) 来获得所需的行为。

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