如果调用了另一个函数，则TkInter帧不会加载

Question

    #!/usr/bin/env python3
    import sys
    import MySQLdb

    if sys.version_info[0] == 2:
        from Tkinter import *
        import Tkinter as ttk
    else:
        from tkinter import *
        import tkinter as ttk

    class Fullscreen_Window:
        def __init__(self):
            self.tk = Tk()
            self.frame = Frame(self.tk)
            self.frame.pack()
            ttk.Button(self.tk, text="hello world").pack()

            self.tk.attributes('-zoomed', True)
            self.state = False
            self.tk.bind("<F11>", self.toggle_fullscreen)
            self.tk.bind("<Escape>", self.end_fullscreen)

            print("init running")
            self.listen_rfid() # Commenting this out makes the GUI appear, uncommenting means no GUI :(

        def toggle_fullscreen(self, event=None):
            self.state = not self.state  # Just toggling the boolean
            self.tk.attributes("-fullscreen", self.state)
            print("Toggling")
            return "break"

        def end_fullscreen(self, event=None):
            self.state = False
            self.tk.attributes("-fullscreen", False)
            return "break"

        def listen_rfid(self):
            print("Main loop running")
            dbHost = 'localhost'
            dbName = 'python'
            dbUser = 'python'
            dbPass = 'PASSWORD'

            dbConnection = MySQLdb.connect(host=dbHost, user=dbUser, passwd=dbPass, db=dbName)
            cur = dbConnection.cursor(MySQLdb.cursors.DictCursor)

            with open('/dev/stdin', 'r') as tty:
                while True:
                    RFID_input = tty.readline().rstrip()
                    cur.execute("SELECT * FROM access_list WHERE rfid_code = '%s'" % (RFID_input))

                    if cur.rowcount != 1:
                        print("ACCESS DENIED")
                    else:
                        user_info = cur.fetchone()
                        print("Welcome %s!!" % (user_info['name']))


            tty.close()
            listen_rfid()

    if __name__ == '__main__':
        w = Fullscreen_Window()
        w.tk.mainloop()

我确信这是一个非常简单的东西，但由于我是一个Python/tKinter n00b，它打败了我，我已经完成了谷歌搜索。感激地得到的任何帮助：）

Answer 1

Tkinter（和所有GUI）有一个称为mainloop的无限循环，它保持GUI的活动和响应。当您进行另一个无限循环(while true)时，您将阻塞tkinter的mainloop；并且GUI失败。您需要将循环放在单独的线程中，或者使用TKinter的mainloop来完成您的工作。由于您使用的是阻塞readline，所以线程是最好的方法。作为猜测,请将您的呼叫替换为以下内容：

from threading import Thread
t = Thread(target=self.listen_rfid)
t.daemon = True # this line tells the thread to quit if the GUI (master thread) quits.
t.start()

编辑：顺便说一句，你的进口非常糟糕。“ttk”是tkinter的子集，而不是别名，别名“tk”通常用于tkinter，通配符导入是不好的，应该避免。以下是tkinter导入的外观：

try:
    # python 2
    import Tkinter as tk
    import ttk
except ImportError:
    # python 3
    import tkinter as tk
    from tkinter import ttk

然后使用适当的前缀：

self.tk = tk.Tk()
self.frame = tk.Frame(self.tk)