Tkinter GUI 在循环运行时冻结

Question

我是python编码的新手，我一直在做一个项目，可以根据所选颜色点击图像。我一直在使用一个程序，当我单击开始按钮时，它会循环搜索 50 次。但是，我一直在尝试实现停止按钮，但问题是我的代码在循环运行时冻结。有什么想法吗？

我

听说过尝试线程，但它似乎非常复杂，并且我无法正确遵循与我的代码相关的任何教程。顺便说一下，搜索的图像一直在测试我一直使用的图像存储在程序文件中。

from imagesearch import *
import pyautogui
import tkinter as tk
from tkinter import *
from tkinter.ttk import *
import time
import threading

# ---Defined Programs---
def run():
    global enterColor
    enterColor = str(enterColorField.get())
    program(enterColor)

def program(color):
    whitePos = imagesearch_numLoop(str(color) + ".PNG", 0, 50)
    pyautogui.moveTo(whitePos[0] + 20, whitePos[1] + 10)
    pyautogui.click()

def stop():
    print("Placeholder")

# ---Main Runner---
window = tk.Tk()
window.geometry("250x250")
window.configure(background="#181b54")
app = tk.Frame(window)
app.grid()
enterColorLabel = tk.Label(window, text="Enter Color:", bg="#181b54", fg="white")
enterColorLabel.place(x=10, y=50)
enterColorField = Combobox(window)
enterColorField['values'] = ("Black", "White")
enterColorField.current("0")  # set the selected item
enterColorField.place(x=10, y=70)
submitButton = tk.Button(window, text="Start", bg="#66ff00", command=run)
submitButton.place(x=10, y=130)
stopButton = tk.Button(window, text="Stop", bg="red", command=stop)
stopButton.place(x=50, y=130)
window.mainloop()

#---New Python Script---
import cv2
import numpy as np
import pyautogui
import random
import time
def imagesearch_numLoop(image, timesample, maxSamples, precision=0.8):
    pos = imagesearch(image, precision)
    count = 0
    while pos[0] == -1:
        print(image+" not found, waiting")
        count = count + 1
        if count>maxSamples:
            break
        pos = imagesearch(image, precision)
    return pos

每当单击开始时，整个代码都会冻结。我什至不能(x(出去。

Answer 1

这是一个希望简单的多处理配方，可以为您工作。我们将有三个主要功能。第一个将是一个示例循环，您将在其中放置处理。我在函数中包含参数，以向您展示在使用多处理时可以传递 args 和 kwarg。

def loop(a, b, c, d):
     # Will just sleep for 3 seconds.. simulates whatever processing you do.
    time.sleep(3)
    return

接下来是我们将用于对多处理进程进行排队的函数。

def queue_loop():
    p = multiprocessing.Process(target = loop, 
                                args = (1, 2),
                                kwargs = {"c": 3, "d": 4})
    # You can pass args and kwargs to the target function like that
    # Note that the process isn't started yet. You call p.start() to activate it.
    p.start()
    check_status(p) # This is the next function we'll define.
    return

然后，您可能有兴趣了解流程在整个执行过程中的状态。例如，有时需要在运行命令时禁用某些按钮。

def check_status(p):
    """ p is the multiprocessing.Process object """
    if p.is_alive(): # Then the process is still running
        label.config(text = "MP Running")
        mp_button.config(state = "disabled")
        not_mp_button.config(state = "disabled")
        root.after(200, lambda p=p: check_status(p)) # After 200 ms, it will check the status again.
    else:
        label.config(text = "MP Not Running")
        mp_button.config(state = "normal")
        not_mp_button.config(state = "normal")
    return

将

所有这些放在一个片段中：

import tkinter as tk
import multiprocessing
import time
def loop(a, b, c, d):
     # Will just sleep for 3 seconds.. simulates whatever processing you do.
    time.sleep(3)
    return
def queue_loop():
    p = multiprocessing.Process(target = loop, 
                                args = (1, 2),
                                kwargs = {"c": 3, "d": 4})
    # You can pass args and kwargs to the target function like that
    # Note that the process isn't started yet. You call p.start() to activate it.
    p.start()
    check_status(p) # This is the next function we'll define.
    return
def check_status(p):
    """ p is the multiprocessing.Process object """
    if p.is_alive(): # Then the process is still running
        label.config(text = "MP Running")
        mp_button.config(state = "disabled")
        not_mp_button.config(state = "disabled")
        root.after(200, lambda p=p: check_status(p)) # After 200 ms, it will check the status again.
    else:
        label.config(text = "MP Not Running")
        mp_button.config(state = "normal")
        not_mp_button.config(state = "normal")
    return

if __name__ == "__main__":
    root = tk.Tk()
    mp_button = tk.Button(master = root, text = "Using MP", command = queue_loop)
    mp_button.pack()
    label = tk.Label(master = root, text = "MP Not Running")
    label.pack()
    not_mp_button = tk.Button(master = root, text = "Not MP", command = lambda: loop(1,2,3,4))
    not_mp_button.pack()
    root.mainloop()

结果是，当您单击"使用 MP"按钮时，命令按钮将被禁用，并且该过程将在不冻结您的 UI 的情况下启动。单击"非MP"按钮将像"正常"一样启动该功能，并冻结您的UI，正如您在自己的代码中注意到的那样。

Answer 2

一个简单的答案是你不能在GUI设计中使用while循环。

但您可以改用该方法.after(delay, callback=None)。

下面是一个示例：

from tkinter import *
root = Tk()
def loop():
    print("Hi!")
    root.after(1000, loop) # 1000 is equal to 1 second.
root.after(1000, loop) # This line is to call loop() in 1 second.
root.mainloop()