如何触发 Tkinter 命令中按钮的更改？

Question

我是 TKinter 的新手。我需要在单击时更改 button 及其 state 的文本，然后执行一些操作，最后再次更改其文本和状态。

问题是更改仅在函数结束后应用，跳过了状态和文本的第一次更改。它永远不会将 Buttons 文本更改为 "loading" 并且按钮永远不会被禁用。

这是我遇到的问题的代码：

#!/usr/bin/env python
import tkinter as tk
import time


class Application(tk.Frame):

    def __init__(self, master=None):
        super().__init__(master)
        self.master = master
        self.pack(fill=tk.BOTH, expand=1)
        self.create_widgets()

    def create_widgets(self):
        self.master.title("CW POS")

        cierre = tk.Button(
            self.master,
            command=self.re_imprimir_ultimo_cierre)

        cierre["text"] = "foo"
        cierre.pack(fill=tk.BOTH, expand=1)
        self._cierre = cierre

        salir = tk.Button(self.master, text="quit", command=self.salir)
        salir.pack(fill=tk.BOTH, expand=1)


    def salir(self):
        exit()

    def re_imprimir_ultimo_cierre(self):
        self._cierre["text"] = "Loading..."
        self._cierre["state"] = tk.DISABLED

        # TODO: magic
        time.sleep(2)

        self._cierre["text"] = "foo"
        self._cierre["state"] = tk.NORMAL



root = tk.Tk()
root.geometry("240x180")
root.resizable(False, False)
app = Application(root)
root.mainloop()

如何在按钮进行计算时让按钮显示 text="loading" 和 state=DISABLED？

Answer 1

这个问题有一个非常快速的修复方法，您只需更新按钮，将其文本更改为 "Loading" (self._cierre["text"] = "Loading...")

    def re_imprimir_ultimo_cierre(self):
        self._cierre["text"] = "Loading..."
        self._cierre["state"] = tk.DISABLED

        self._cierre.update() # This is the line I added

        # TODO: magic
        time.sleep(2)

        self._cierre["text"] = "foo"
        self._cierre["state"] = tk.NORMAL

这只是在您更改文本和状态后更新按钮状态。

From what I understand this is because a button will run all the code within its command, before updating anything on the screen, so you essentially have to force the button to update itself within its command.

希望这对您有所帮助:)

如何触发 Tkinter 命令中按钮的更改？

How to trigger changes in button in a comand in Tkinter?

python

user-interface

tk

tkinter

python-3.x