如何根据来自单独线程的特定值更新小部件?

How can I update a widget according to a certain value that comes from a seperate thread?

我的 GUI 应用程序有多个屏幕 (3),每个屏幕都包含用户可以更改的某些文本小部件(我根据 Whosebug 中众所周知的解决方案建立了这个多屏幕 GUI)。填写某个屏幕的字段后,用户可以 "Burn" 这些值到某个硬件。为了能够 "Burn" 到 HW,我在应用 运行.

后立即启动到 HW 的 Telnet 会话(IP 是硬编码的)

每个框架都显示状态栏,我想用 Telnet 连接到 HW 的当前状态更新它。为了维护 Telnet 连接,我使用了一个单独的线程。而且我还使用了一个队列来更新当前状态。

当 Telnet 会话状态更改时,我可以通过简单地打印到控制台来更新。如果 Telnet 会话因任何好的(或坏的)原因断开连接,我也能够恢复它。

我的问题是我无法用当前状态更新状态栏(状态标签)。在下面的代码中,您可以看到我已尝试在状态更改时生成一个事件。但是,它没有完成工作。如何使用实际状态更新状态栏?

编辑后

(我费了很大的劲,去掉了200多行代码):

from tkinter import font, ttk
import tkinter as tk
from re import match

import telnetlib
import threading
import queue

import time

LARGE_FONT= ("Verdana", 12)
Current_PN = '123456789'    # This global ver is used for the purpose of automatic PN fill

HOST = '10.0.1.235'
PORT = 23

telnet_session = None       # After I create the Telnet session I will keep track with this variable
connected = False

class BurningApp(tk.Tk):
    def __init__(self, *args, **kwargs):

        tk.Tk.__init__(self, *args, **kwargs)
        container = tk.Frame(self)

        container.pack(side="top", fill="both", expand = True)

        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.title('Burning App')  #handling the application's Window title

        w = 1000    # Windows width
        h = 600     # Windows height

        ws = self.winfo_screenwidth()       # Screen resolution width
        hs = self.winfo_screenheight()     # Screen resolution height

        # w = ws * 0.8    # Fit the GUI width to 80% percent of the screen
        # h = hs * 0.8    # Fit the GUI height to 80% percent of the screen

        x = (ws/2) - (w/2)      # X coordinate for the purpose of GUI placement
        y = (hs/2) - (h/2)      # X coordinate for the purpose of GUI placement



        self.resizable(width=False, height=False)

        self.geometry('%dx%d+%d+%d'%(w,h,x,y))

        self.frames = {}

        for F in (MainScreen, FirstScreen, SecondScreen):

            frame = F(container, self)

            self.frames[F] = frame

            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame(MainScreen)

        # Start the Telnet session
        self.connect_to_uut()

        # Create the queue that will hold the status
        self.status_queue = queue.Queue()

        # Set up the thread to do asynchronous I/O
        self.running = 1    # True
        self.thread = threading.Thread(target=self.workerThread)
        self.thread.start()

        # Start the periodic call in the GUI to check if the queue contains
        # anything
        self.periodicCall()

    def show_frame(self, cont):
        '''
        This function is being used in order to raise a frame on demand
        '''
        frame = self.frames[cont]
        frame.tkraise()


    def connect_to_uut(self, Retry=5):
        '''
        This functions is used for the purpose of connecting to the UUT
        '''
        global telnet_session
        global connected

        for _ in range(Retry):
            try:
                telnet_session = telnetlib.Telnet(HOST, PORT, timeout=5)
                connected = True
                self.event_generate("<<StatusChange>>")
                break
            except:
                connected = False
                self.event_generate("<<StatusChange>>")
                continue


    def periodicCall(self):
        """
        Check every 10 sec if there is something new in the queue.
        This is actually Telnet connection status check
        """
        self.processIncoming()
        if not self.running:
            # This is the brutal stop of the system. You may want to do
            # some cleanup before actually shutting it down.
            import sys
            sys.exit(1)
        self.after(10000, self.periodicCall)


    def processIncoming(self):
        """
        Handle all the messages currently in the queue (if any).
        """
#         global connected

        while self.status_queue.qsize():
            try:
                msg = self.status_queue.get(0)
                # Check contents of message and do what it says
                # As a test, I simply print it
                print(msg)
#                 if not connected:
#                     self.connect_to_uut()
            except queue.Empty:
                pass

    def workerThread(self):
        """
        This is where we handle the asynchronous I/O.
        """
        global telnet_session
        global connected

        while self.running:
            time.sleep(5)
            try:
                telnet_session.sock.send(telnetlib.IAC + telnetlib.NOP)
                connected = True
                msg = 'Connected'
            except:
                connected = False
                msg = 'Disconnected'       #The Actual Status of the Telnet session
                self.event_generate("<<StatusChange>>")
                if not connected:
                    self.connect_to_uut()

            self.status_queue.put(msg)



class MainScreen(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)

        self.Button_Font_Style1 = font.Font(family='Helvetica', size=30, weight='bold')
        self.Status_BasicStyle = font.Font(family='Helvetica', size=10, weight='bold')

        self.my_string_var = tk.StringVar()

        self.button1 = tk.Button(self, text="PROGRAM 1",
                            command=lambda: controller.show_frame(FirstScreen),
                             width=30, font=self.Button_Font_Style1, bd=5)
        self.button1.pack(pady=8)

        self.button2 = tk.Button(self, text="PROGRAM 2",
                            command=lambda: controller.show_frame(FirstScreen),
                             width=30, font=self.Button_Font_Style1, bd=5)
        self.button2.pack(pady=8)

        self.button3 = tk.Button(self, text="PROGRAM 3",
                            command=lambda: controller.show_frame(FirstScreen),
                             width=30, font=self.Button_Font_Style1, bd=5)
        self.button3.pack(pady=8)

        self.button4 = tk.Button(self, text="PROGRAM 4",
                            command=lambda: controller.show_frame(SecondScreen),
                            width=30, font=self.Button_Font_Style1, bd=5) 
        self.button4.pack(pady=8)

        self.button5 = tk.Button(self, text="PROGRAM FAN ",
                            command=lambda: controller.show_frame(FirstScreen),
                            width=30, font=self.Button_Font_Style1, bd=5) 
        self.button5.pack(pady=8)

        self.status = tk.Label(self, textvariable=self.my_string_var, bd=2, relief=tk.SUNKEN, anchor=tk.W, font=self.Status_BasicStyle, fg="black")        
        self.my_string_var.set('Connecting...')
        self.status.pack(side="bottom" , fill="x")

class FirstScreen(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)

        self.valid_string_color = "springgreen3"
        self.invalid_string_color = "red2"

        self.main_frame = tk.Frame(self)

        self.Button_Font_Style1 = font.Font(family='Helvetica', size=20, weight='bold')
        self.Lable_Font_Style1 = font.Font(family='Helvetica', size=20, weight='bold')
        self.Status_BasicStyle = font.Font(family='Helvetica', size=10, weight='bold')

        self.SN_Label = tk.Label(self.main_frame, text="Serial Number", font=self.Lable_Font_Style1)
        self.SN_Label.grid(row=0, column=0, pady=10)     # Y axis padding was added only to the label. This padding effects the whole line

        self.SN_field = tk.Text(self.main_frame, height=1, width=30, font=self.Lable_Font_Style1)
        self.SN_field.grid(row=0, column=1)

        self.PN_Label = tk.Label(self.main_frame, text="Part Number", font=self.Lable_Font_Style1)
        self.PN_Label.grid(row=1, column=0, pady=10)     # Y axis padding was added only to the label. This padding effects the whole line

        self.PN_field = tk.Text(self.main_frame, height=1, width=30, font=self.Lable_Font_Style1)
        self.PN_field.grid(row=1, column=1)

        self.HwVer_Label = tk.Label(self.main_frame, text="HW Version", font=self.Lable_Font_Style1)
        self.HwVer_Label.grid(row=2, column=0, pady=10)     # Y axis padding was added only to the label. This padding effects the whole line

        self.HwVer_field = tk.Text(self.main_frame, height=1, width=30, font=self.Lable_Font_Style1)
        self.HwVer_field.grid(row=2, column=1)

        self.button2 = tk.Button(self.main_frame, text="Burn",
                            font=self.Button_Font_Style1, bd=5)
        self.button2.grid(row=3, columnspan=2, pady=(20,0))

        self.main_frame.pack()

        self.my_string_var = tk.StringVar()

        self.status = tk.Label(self, textvariable=self.my_string_var, bd=2, relief=tk.SUNKEN, anchor=tk.W, font=self.Status_BasicStyle, fg='black')        
        self.my_string_var.set('Connecting...')
        self.status.pack(side="bottom" , fill="x")
        self.status.bind("<<StatusChange>>", self.statuschange)     # React to the status change event and change the status label accordingly

        self.button1 = tk.Button(self, text="Main Menu",
                            command=lambda: controller.show_frame(MainScreen),
                            font=self.Button_Font_Style1, bd=5)
        self.button1.pack(side="bottom", pady=(0,20))


    def statuschange(self):
        global connected

        if connected:
            self.my_string_var.set('Connected')
            self.status.config(font=self.Status_ConnectedStyle, fg='springgreen3')
        else:
            self.my_string_var.set('Disonnected')
            self.status.config(font=self.Status_DisconnectedStyle, fg='red2')

class SecondScreen(tk.Frame):    
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)

        self.valid_string_color = "springgreen3"
        self.invalid_string_color = "red2"

        self.main_frame = tk.Frame(self)

        self.Button_Font_Style1 = font.Font(family='Helvetica', size=20, weight='bold')
        self.Lable_Font_Style1 = font.Font(family='Helvetica', size=20, weight='bold')
        self.Status_BasicStyle = font.Font(family='Helvetica', size=5, weight='bold')

        self.SN_Label = tk.Label(self.main_frame, text="Serial Number", font=self.Lable_Font_Style1)
        self.SN_Label.grid(row=0, column=0, pady=10)     # Y axis padding was added only to the label. This padding effects the whole line

        self.SN_field = tk.Text(self.main_frame, height=1, width=30, font=self.Lable_Font_Style1)
        self.SN_field.grid(row=0, column=1)

        self.PN_Label = tk.Label(self.main_frame, text="Part Number", font=self.Lable_Font_Style1)
        self.PN_Label.grid(row=1, column=0, pady=10)     # Y axis padding was added only to the label. This padding effects the whole line

        self.PN_field = tk.Text(self.main_frame, height=1, width=30, font=self.Lable_Font_Style1)
        self.PN_field.grid(row=1, column=1)

        self.HwVer_Label = tk.Label(self.main_frame, text="HW Version", font=self.Lable_Font_Style1)
        self.HwVer_Label.grid(row=2, column=0, pady=10)     # Y axis padding was added only to the label. This padding effects the whole line

        self.HwVer_field = tk.Text(self.main_frame, height=1, width=30, font=self.Lable_Font_Style1)
        self.HwVer_field.grid(row=2, column=1)

        self.button2 = tk.Button(self.main_frame, text="Burn",
                            font=self.Button_Font_Style1, bd=5)
        self.button2.grid(row=3, columnspan=2, pady=(20,0))

        self.main_frame.pack()

        self.my_string_var = tk.StringVar()

        self.status = tk.Label(self, textvariable=self.my_string_var, bd=2, relief=tk.SUNKEN, anchor=tk.W, font=self.Status_BasicStyle, fg="black")        
        self.my_string_var.set('Connecting...')
        self.status.pack(side="bottom" , fill="x")
        self.status.bind("<<StatusChange>>", self.statuschange)     # React to the status change event and change the status label accordingly

        self.button1 = tk.Button(self, text="Main Menu",
                            command=lambda: controller.show_frame(MainScreen),
                            font=self.Button_Font_Style1, bd=5)
        self.button1.pack(side="bottom", pady=(0,20))


    def statuschange(self):
        global connected

        if connected:
            self.my_string_var.set('Connected')
            self.status.config(font=self.Status_ConnectedStyle, fg='springgreen3')
        else:
            self.my_string_var.set('Disonnected')
            self.status.config(font=self.Status_DisconnectedStyle, fg='red2')


def main():
    app = BurningApp()        
    app.mainloop()

if __name__ == '__main__':
    main()

顺便说一下,我知道我缺少应该更新 MainScreen 中状态栏的方法 Class

正如我承诺的那样,这里是最精简的代码。我留下了一些"fraems",只是为了能够看到每一帧都显示正确的状态,我去掉了不相关的字段

from tkinter import font, ttk
import tkinter as tk
from re import match

import telnetlib
import threading
import queue

import time

LARGE_FONT= ("Verdana", 12)
Current_PN = '123456789'    # This global ver is used for the purpose of automatic PN fill

HOST = '10.0.1.235'
PORT = 23

telnet_session = None       # After I create the Telnet session I will keep track with this variable
connected = False

class BurningApp(tk.Tk):
    def __init__(self, *args, **kwargs):

        tk.Tk.__init__(self, *args, **kwargs)
        container = tk.Frame(self)

        container.pack(side="top", fill="both", expand = True)

        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.title('Burning App')  #handling the application's Window title

        w = 1000    # Windows width
        h = 600     # Windows height

        ws = self.winfo_screenwidth()       # Screen resolution width
        hs = self.winfo_screenheight()     # Screen resolution height

        # w = ws * 0.8    # Fit the GUI width to 80% percent of the screen
        # h = hs * 0.8    # Fit the GUI height to 80% percent of the screen

        x = (ws/2) - (w/2)      # X coordinate for the purpose of GUI placement
        y = (hs/2) - (h/2)      # X coordinate for the purpose of GUI placement



        self.resizable(width=False, height=False)

        self.geometry('%dx%d+%d+%d'%(w,h,x,y))

        self.frames = {}

        for F in (MainScreen, FirstScreen, SecondScreen):

            frame = F(container, self)

            self.frames[F] = frame

            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame(MainScreen)

        # Start the Telnet session
        self.connect_to_uut()

        # Create the queue that will hold the status
        self.status_queue = queue.Queue()

        # Set up the thread to do asynchronous I/O
        self.running = 1    # True
        self.thread = threading.Thread(target=self.workerThread)
        self.thread.start()

        # Start the periodic call in the GUI to check if the queue contains
        # anything
        self.periodicCall()

    def show_frame(self, cont):
        '''
        This function is being used in order to raise a frame on demand
        '''
        frame = self.frames[cont]
        frame.tkraise()


    def connect_to_uut(self, Retry=5):
        '''
        This functions is used for the purpose of connecting to the UUT
        '''
        global telnet_session
        global connected

        for _ in range(Retry):
            try:
                telnet_session = telnetlib.Telnet(HOST, PORT, timeout=5)
                connected = True
                self.event_generate("<<StatusChange>>")
                break
            except:
                connected = False
                self.event_generate("<<StatusChange>>")
                continue


    def periodicCall(self):
        """
        Check every 10 sec if there is something new in the queue.
        This is actually Telnet connection status check
        """
        self.processIncoming()
        if not self.running:
            # This is the brutal stop of the system. You may want to do
            # some cleanup before actually shutting it down.
            import sys
            sys.exit(1)
        self.after(10000, self.periodicCall)


    def processIncoming(self):
        """
        Handle all the messages currently in the queue (if any).
        """
#         global connected

        while self.status_queue.qsize():
            try:
                msg = self.status_queue.get(0)
                # Check contents of message and do what it says
                # As a test, I simply print it
                print(msg)
#                 if not connected:
#                     self.connect_to_uut()
            except queue.Empty:
                pass

    def workerThread(self):
        """
        This is where we handle the asynchronous I/O.
        """
        global telnet_session
        global connected

        while self.running:
            time.sleep(5)
            try:
                telnet_session.sock.send(telnetlib.IAC + telnetlib.NOP)
                connected = True
                msg = 'Connected'
            except:
                connected = False
                msg = 'Disconnected'       #The Actual Status of the Telnet session
                self.event_generate("<<StatusChange>>")
                if not connected:
                    self.connect_to_uut()

            self.status_queue.put(msg)



class MainScreen(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)

        self.Button_Font_Style1 = font.Font(family='Helvetica', size=30, weight='bold')
        self.Status_BasicStyle = font.Font(family='Helvetica', size=10, weight='bold')

        self.my_string_var = tk.StringVar()

        self.button1 = tk.Button(self, text="PROGRAM 1",
                            command=lambda: controller.show_frame(FirstScreen),
                             width=30, font=self.Button_Font_Style1, bd=5)
        self.button1.pack(pady=8)

        self.button2 = tk.Button(self, text="PROGRAM 2",
                            command=lambda: controller.show_frame(FirstScreen),
                             width=30, font=self.Button_Font_Style1, bd=5)
        self.button2.pack(pady=8)

        self.status = tk.Label(self, textvariable=self.my_string_var, bd=2, relief=tk.SUNKEN, anchor=tk.W, font=self.Status_BasicStyle, fg="black")        
        self.my_string_var.set('Connecting...')
        self.status.pack(side="bottom" , fill="x")

class FirstScreen(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)

        self.Button_Font_Style1 = font.Font(family='Helvetica', size=20, weight='bold')
        self.Status_BasicStyle = font.Font(family='Helvetica', size=10, weight='bold')
        self.my_string_var = tk.StringVar()

        self.status = tk.Label(self, textvariable=self.my_string_var, bd=2, relief=tk.SUNKEN, anchor=tk.W, font=self.Status_BasicStyle, fg='black')        
        self.my_string_var.set('Connecting...')
        self.status.pack(side="bottom" , fill="x")
        self.status.bind("<<StatusChange>>", self.statuschange)     # React to the status change event and change the status label accordingly

        self.button1 = tk.Button(self, text="Main Menu",
                            command=lambda: controller.show_frame(MainScreen),
                            font=self.Button_Font_Style1, bd=5)
        self.button1.pack(side="bottom", pady=(0,20))


    def statuschange(self):
        global connected

        if connected:
            self.my_string_var.set('Connected')
            self.status.config(font=self.Status_ConnectedStyle, fg='springgreen3')
        else:
            self.my_string_var.set('Disonnected')
            self.status.config(font=self.Status_DisconnectedStyle, fg='red2')

class SecondScreen(tk.Frame):    
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)

        self.Button_Font_Style1 = font.Font(family='Helvetica', size=20, weight='bold')
        self.Status_BasicStyle = font.Font(family='Helvetica', size=5, weight='bold')
        self.my_string_var = tk.StringVar()

        self.status = tk.Label(self, textvariable=self.my_string_var, bd=2, relief=tk.SUNKEN, anchor=tk.W, font=self.Status_BasicStyle, fg="black")        
        self.my_string_var.set('Connecting...')
        self.status.pack(side="bottom" , fill="x")
        self.status.bind("<<StatusChange>>", self.statuschange)     # React to the status change event and change the status label accordingly

        self.button1 = tk.Button(self, text="Main Menu",
                            command=lambda: controller.show_frame(MainScreen),
                            font=self.Button_Font_Style1, bd=5)
        self.button1.pack(side="bottom", pady=(0,20))


    def statuschange(self):
        global connected

        if connected:
            self.my_string_var.set('Connected')
            self.status.config(font=self.Status_ConnectedStyle, fg='springgreen3')
        else:
            self.my_string_var.set('Disonnected')
            self.status.config(font=self.Status_DisconnectedStyle, fg='red2')


def main():
    app = BurningApp()        
    app.mainloop()

if __name__ == '__main__':
    main()

这些调整应该可以解决您的问题:

self.status.config(font=self.Status_ConnectedStyle,
text=self.my_string_var,fg='springgreen3')

我终于完成了,我可以更新状态栏,请参阅下面的信息。

我在每个框架中添加了以下方法。此方法的目的是定期检查保存 Telnet 会话状态(连接)的标志。所以我仍然使用相同的线程:主 GUI 线程和另一个维护 Telnet 会话的线程。为了"activate"这个方法,我在某个帧被提升后启动它("frame_was_raised"方法)

def update_statusbar(self):
        '''Poll the Telnet Session Status for the purpose of update'''
        global connected

        if connected:
            self.my_string_var.set('Connected')
            self.status.config(fg='springgreen3')
        else:
            self.my_string_var.set('Disconnected')
            self.status.config(fg='red2')

        self.after(2000, self.update_statusbar)