Python 如何在关闭MessageBox之前防止TKinterGrab_Set()失败

IIUC，您可以派生simpledialog.Dialog的子类来创建自定义对话框并覆盖所需的方法.

下面是一个例子:

import tkinter as tk
from tkinter import Menu, simpledialog, ttk
from tkinter.messagebox import askyesno


class Test(tk.Tk):
    def builtin(self, wtitle):
        print("Button One")
        answer = askyesno(title=wtitle, message="Click something", icon="info")
        print("User pressed: %s" % answer)

    def custom(self, wtitle):
        print("Button Two")
        answer = popup_msg(
            self, wtitle="My Custom MessageBox", msg="This is custom MessageBox"
        )
        print("User pressed: %s" % answer)

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        self.wm_title("Test")
        self.geometry("300x100")

        frame = ttk.Frame(self)

        button_one = ttk.Button(
            self, text="Built-in", command=lambda: self.builtin("Built-In")
        )
        button_two = ttk.Button(
            self, text="Custom", command=lambda: self.custom("Custom")
        )

        button_one.pack(padx=5, pady=5)
        button_two.pack(padx=5, pady=5)
        frame.pack()


class MessageBox(simpledialog.Dialog):
    def __init__(self, master, *args, **kwargs):
        self.sample_var = tk.StringVar()
        self.sample_var.set("No")

        self.label_var = tk.StringVar()
        self.label_var.set(kwargs.pop("msg", "default msg"))

        simpledialog.Dialog.__init__(
            self, master, title=kwargs.pop("wtitle", "default title"), *args, **kwargs
        )

    def body(self, master):
        """create dialog body.

        return widget that should have initial focus.
        This method should be overridden, and is called
        by the __init__ method.
        """

        tk.Label(master, textvariable=self.label_var).grid(row=0, columnspan=2)

        self.btn_yes = tk.Button(
            master, text="Yes", command=lambda: self._button_yes(master)
        ).grid(row=1, column=0)

        self.btn_no = tk.Button(
            master, text="No", command=lambda: self._button_no(master)
        ).grid(row=1, column=1)

    def _button_yes(self, master):
        self.sample_var.set("Yes")
        self.ok()

    def _button_no(self, master):
        self.sample_var.set("No")
        self.ok()

    def validate(self):
        """validate the data

        This method is called automatically to validate the data before the
        dialog is destroyed. By default, it always validates OK.
        """

        return 1  # override

    def apply(self):
        """process the data

        This method is called automatically to process the data, *after*
        the dialog is destroyed. By default, it does nothing.
        """
        self.result = self.sample_var.get()

    def buttonbox(self):
        """Override default simpledialog.Dialog buttons"""
        pass


def popup_msg(root, wtitle, msg):
    res = MessageBox(app, wtitle=wtitle, msg=msg)
    return res.result


app = Test()
app.mainloop()

当您点击Custom按钮时，您将看到:

然后，当您单击Yes/No时，对话框关闭，程序打印User pressed: Yes/No