使用来自第二个线程的数据更新Tkinter-GUI中的数据

时间:2017-12-21 23:34:58

标签: python asynchronous tkinter python-asyncio python-multithreading

问题是我的解决方案是否是使用另一个线程的数据更新Tkinter-GUI的保存和pythonic方式?需要Lock吗?或者Queue怎么能帮到这里?这个例子运行正常,但原始应用程序有更复杂的数据需要处理。

请关注最小工作示例中的AsyncioThread.create_dummy_data()。该示例具有两个线程。一个运行 Tkinter -mainloop,第二个线程运行 asyncio -loop。 asyncio循环模拟获取一些数据并使用此数据刷新一些tkinter.Label

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# restrict to Python3.5 or higher because of asyncio syntax

# based on <https://stackoverflow.com/a/47920128/4865723>

from tkinter import *
import asyncio
import threading
import random


class AsyncioThread(threading.Thread):
    def __init__(self, asyncio_loop, theWindow):
        self.asyncio_loop = asyncio_loop
        self.theWindow = theWindow
        self.maxData = len(theWindow.varData)
        threading.Thread.__init__(self)


    def run(self):
        self.asyncio_loop.run_until_complete(self.do_data())


    async def do_data(self):
        """ Creating and starting 'maxData' asyncio-tasks. """
        tasks = [
            self.create_dummy_data(number)
            for number in range(self.maxData)
        ]
        completed, pending = await asyncio.wait(tasks)
        results = [task.result() for task in completed]
        print('\n'.join(results))


    async def create_dummy_data(self, number):
        """ One task. """
        sec = random.randint(1, 3)
        data = '{}:{}'.format(number, random.random())
        await asyncio.sleep(sec)

        # IS THIS SAVE?
        self.theWindow.varData[number].set(data)
        print('Thread-ID: {}\tsec: {}\n\t{}' \
               .format(threading.get_ident(), sec, data))

        return data


class TheWindow:
    def __init__(self, maxData):
        # asyncio loop will run in an extra Thread
        self.asyncio_loop = asyncio.get_event_loop()

        # the GUI main object
        self.root = Tk()

        # create the data variable
        self.varData = []
        for i in range(maxData):
            self.varData.append(StringVar())
            self.varData[i].set('<default>')

        # Button to start the asyncio tasks
        Button(master=self.root,
               text='Start Asyncio Tasks',
               command=lambda:self.do_asyncio()).pack()
        # Frames to display data from the asyncio tasks
        for i in range(maxData):
            Label(master=self.root, textvariable=self.varData[i]).pack()
        # Button to check if the GUI is freezed
        Button(master=self.root,
               text='Freezed???',
               command=self.do_freezed).pack()

    def do_freezed(self):
        """ Button-Event-Handler to see if a button on GUI works.
            The GOAL of this example is to make this button clickable
            while the other thread/asyncio-tasks are working. """
        print('Tkinter is reacting. Thread-ID: {}'
              .format(threading.get_ident()))


    def do_asyncio(self):
        """ Button-Event-Handler starting the asyncio part in a separate thread. """
        thread = AsyncioThread(self.asyncio_loop, self)
        thread.start()


if __name__ == '__main__':
    window = TheWindow(5)
    window.root.mainloop()

真正的应用

此示例已简化。真正的应用程序是从许多不同的网站下载(使用feedparser)数百个xml文件(新闻源)。 结果显示在Tkinter.Treeview中,其中每个xml文件在TreeView中都有一个条目。即G。 xml文件中的条目数显示在TreeView(例如“时间杂志(12个条目)”)的条目中。 这应该在每次下载xml文件完成后完成,所有 xml文件下载完成后

2 个答案:

答案 0 :(得分:2)

此解决方案基于其他人的评论。它使用queue.Queue在两个线程之间共享数据。 Tkinter GUI / Thread使用1秒计时器来检查新数据是否在队列中并使用它来刷新其标签。

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# based on <https://stackoverflow.com/a/47920128/4865723>

from tkinter import *
import asyncio
import threading
import random
import queue


class AsyncioThread(threading.Thread):
    def __init__(self, the_queue, max_data):
        self.asyncio_loop = asyncio.get_event_loop()
        self.the_queue = the_queue
        self.max_data = max_data
        threading.Thread.__init__(self)

    def run(self):
        self.asyncio_loop.run_until_complete(self.do_data())

    async def do_data(self):
        """ Creating and starting 'maxData' asyncio-tasks. """
        tasks = [
            self.create_dummy_data(key)
            for key in range(self.max_data)
        ]
        await asyncio.wait(tasks)

    async def create_dummy_data(self, key):
        """ Create data and store it in the queue. """
        sec = random.randint(1, 10)
        data = '{}:{}'.format(key, random.random())
        await asyncio.sleep(sec)

        self.the_queue.put((key, data))


class TheWindow:
    def __init__(self, max_data):
        # thread-safe data storage
        self.the_queue = queue.Queue()

        # the GUI main object
        self.root = Tk()

        # create the data variable
        self.data = []
        for key in range(max_data):
            self.data.append(StringVar())
            self.data[key].set('<default>')

        # Button to start the asyncio tasks
        Button(master=self.root,
               text='Start Asyncio Tasks',
               command=lambda: self.do_asyncio()).pack()
        # Frames to display data from the asyncio tasks
        for key in range(max_data):
            Label(master=self.root, textvariable=self.data[key]).pack()
        # Button to check if the GUI is freezed
        Button(master=self.root,
               text='Freezed???',
               command=self.do_freezed).pack()

    def refresh_data(self):
        """
        """
        # do nothing if the aysyncio thread is dead
        # and no more data in the queue
        if not self.thread.is_alive() and self.the_queue.empty():
            return

        # refresh the GUI with new data from the queue
        while not self.the_queue.empty():
            key, data = self.the_queue.get()
            self.data[key].set(data)

        print('RefreshData...')

        #  timer to refresh the gui with data from the asyncio thread
        self.root.after(1000, self.refresh_data)  # called only once!

    def do_freezed(self):
        """ Button-Event-Handler to see if a button on GUI works.
            The GOAL of this example is to make this button clickable
            while the other thread/asyncio-tasks are working. """
        print('Tkinter is reacting. Thread-ID: {}'
              .format(threading.get_ident()))

    def do_asyncio(self):
        """
            Button-Event-Handler starting the asyncio part in a separate
            thread.
        """
        # create Thread object
        self.thread = AsyncioThread(self.the_queue, len(self.data))

        #  timer to refresh the gui with data from the asyncio thread
        self.root.after(1000, self.refresh_data)  # called only once!

        # start the thread
        self.thread.start()


if __name__ == '__main__':
    window = TheWindow(10)
    window.root.mainloop()

此示例基于https://stackoverflow.com/a/47920128/4865723。 不确定这是否是一个优雅的解决方案。请随时编辑此内容。我的目标是让我的问题和答案可以被其他人重复使用。

答案 1 :(得分:0)

我用另一种方式解决了它。 我不是专家,但我发现这个解决方案对我有用。欢迎任何改进!

  1. Tk 中创建 root 对象(通常称为 main())。
  2. Class 中创建一个线程来运行您的应用程序(我假设它是一个 main())并将 root 作为参数传递给它。
  3. root.mainloop()中执行main()
  4. 在应用程序类的 __init__ 中定义您的 GUI 按钮、标签、条目等
  5. 像往常一样使用 Tkinter 方法更新应用程序类中的 GUI 按钮、标签、条目……(get()set()、...)

这是一个获得想法的模板:

from tkinter import *
import _thread


class App(threading.Thread):

    def __init__(self, root, my_param2, my_param3):

        # Creare GUI
        self.root = root

        # Your code here

    def method1(self):
        # Your code here



def main():

    # Create GUI
    root = Tk(className='MyApp')

    # Create 2 threads
    num_threads = 2
    for t in range(num_threads):
    
        try:
            _thread.start_new_thread(App, (root, my_param2, my_param3, ) )

        except:
            print('Error: can not create a thread')

    # tkinter main loop
    root.mainloop()

    print ('You don\'t see this message')


if __name__ == "__main__":

    main()