冻结/挂起 tkinter GUI 等待线程完成

Question

按下按钮后我的界面冻结了。我正在使用线程，但我不确定为什么仍然挂起。任何帮助将不胜感激。提前致谢

class magic:
    def __init__(self):
        self.mainQueue=queue.Queue()

    def addItem(self,q):
        self.mainQueue.put(q)

    def startConverting(self,funcName):
        if(funcName=="test"):
            while not self.mainQueue.empty():
                t = Thread(target = self.threaded_function)
                t.start()
                t.join()

    def threaded_function(self):

        time.sleep(5)
        print(self.mainQueue.get())

m=magic()
def helloCallBack():
   m.addItem("asd")
   m.startConverting("test")  //this line of code is freezing

B = tkinter.Button(top, text ="Hello", command = helloCallBack)

B.pack()
top.mainloop()

Answer 1

这是使用基于 tkinter 的 GUI 执行异步任务的秘诀。我根据所引用的书中的食谱改编了它。您应该能够修改它来执行您需要的操作。

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为了保持 GUI 的响应能力，不需要mainloop()通过执行诸如join()后台线程\xe2\x80\x94 之类的操作来干扰它，这会使 GUI“挂起”直到线程完成。这是通过使用通用after()小部件方法定期轮询a来完成的。Queue

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# from "Python Coobook 2nd Edition", section 11.9, page 439.\n# Modified to work in Python 2 & 3.\nfrom __future__ import print_function\n\ntry:\n    import Tkinter as tk, time, threading, random, Queue as queue\nexcept ModuleNotFoundError:   # Python 3\n    import tkinter as tk, time, threading, random, queue\n\nclass GuiPart(object):\n    def __init__(self, master, queue, end_command):\n        self.queue = queue\n        # Set up the GUI\n        tk.Button(master, text=\'Done\', command=end_command).pack()\n        # Add more GUI stuff here depending on your specific needs\n\n    def processIncoming(self):\n        """ Handle all messages currently in the queue, if any. """\n        while self.queue.qsize():\n            try:\n                msg = self.queue.get_nowait()\n                # Check contents of message and do whatever is needed. As a\n                # simple example, let\'s print it (in real life, you would\n                # suitably update the GUI\'s display in a richer fashion).\n                print(msg)\n            except queue.Empty:\n                # just on general principles, although we don\'t expect this\n                # branch to be taken in this case, ignore this exception!\n                pass\n\n\nclass ThreadedClient(object):\n    """\n    Launch the main part of the GUI and the worker thread. periodic_call()\n    and end_application() could reside in the GUI part, but putting them\n    here means that you have all the thread controls in a single place.\n    """\n    def __init__(self, master):\n        """\n        Start the GUI and the asynchronous threads.  We are in the main\n        (original) thread of the application, which will later be used by\n        the GUI as well.  We spawn a new thread for the worker (I/O).\n        """\n        self.master = master\n        # Create the queue\n        self.queue = queue.Queue()\n\n        # Set up the GUI part\n        self.gui = GuiPart(master, self.queue, self.end_application)\n\n        # Set up the thread to do asynchronous I/O\n        # More threads can also be created and used, if necessary\n        self.running = True\n        self.thread1 = threading.Thread(target=self.worker_thread1)\n        self.thread1.start()\n\n        # Start the periodic call in the GUI to check the queue\n        self.periodic_call()\n\n    def periodic_call(self):\n        """ Check every 200 ms if there is something new in the queue. """\n        self.master.after(200, self.periodic_call)\n        self.gui.processIncoming()\n        if not self.running:\n            # This is the brutal stop of the system.  You may want to do\n            # some cleanup before actually shutting it down.\n            import sys\n            sys.exit(1)\n\n    def worker_thread1(self):\n        """\n        This is where we handle the asynchronous I/O.  For example, it may be\n        a \'select()\'.  One important thing to remember is that the thread has\n        to yield control pretty regularly, be it by select or otherwise.\n        """\n        while self.running:\n            # To simulate asynchronous I/O, create a random number at random\n            # intervals. Replace the following two lines with the real thing.\n            time.sleep(rand.random() * 1.5)\n            msg = rand.random()\n            self.queue.put(msg)\n\n    def end_application(self):\n        self.running = False  # Stops worker_thread1 (invoked by "Done" button).\n\nrand = random.Random()\nroot = tk.Tk()\nclient = ThreadedClient(root)\nroot.mainloop()\n

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