Tkinter键绑定在消息框后不工作

Question

我正在使用计算器，并且遇到了有关我的键绑定的问题。在我的GUI类的启动结束时，会创建一个消息框来解释对用户的绑定。具有讽刺意味的是，这会导致所有绑定在消息框关闭之前不作出响应，并且tkinter窗口被取消选择然后重新选择。绑定编码是这样的：

master.bind('<Delete>', self.delete) 
master.bind('<BackSpace>', self.back) 
master.bind('<Return>', self.equals) 
master.bind('<Insert>', self.add_answer) 

我试图使用focus_set（）但它没有帮助。消息框关闭后，我能做些什么来使键盘绑定立即响应？

这是我的上下文的完整代码。

from tkinter import * 
from tkinter.ttk import * 
from tkinter import messagebox # added by @martineau 

class Logic: 
    def add_digit(self, *args): 
     if type(args[0]) == str: 
      self.expression.append(args[0]) 
     else: 
      self.expression.append(args[0].char) 
     self.labels[1].config(text="".join(self.expression)) 

    def add_operation(self, *args): 
     if type(args[0]) == str: 
      self.expression.append(args[0]) 
     else: 
      self.expression.append(args[0].char) 
     self.labels[1].config(text="".join(self.expression)) 

    def add_answer(self, *args): 
     self.expression.extend(list(self.labels[0]['text'])) 
     self.labels[1].config(text="".join(self.expression)) 

    def delete(self, *args): 
     if self.expression: 
      self.expression = list() 
      self.labels[1].config(text="".join(self.expression)) 
     else: 
      self.labels[0].config(text="") 

    def back(self, *args): 
     self.expression = self.expression[:-1] 
     self.labels[1].config(text="".join(self.expression)) 

    def equals(self, *args): 
     equation = list() 
     number = list() 

     if not self.expression: 
      self.labels[0].config(text='') 

     for value in self.expression: 
      if value in self.numpad_texts: 
       number.append(value) 
      else: 
       if number: 
        equation.append(str(float("".join(number)))) 
        number = list() 
       equation.append(value) 

     if number: 
      try: 
       equation.append(str(float("".join(number)))) 
      except ValueError: 
       messagebox.showerror("Error", "Syntax error: Your expression has incorrect syntax") 

     for i in range(len(equation)): 
      if equation[i] == '(' and i != 0: 
       if equation[i-1] not in self.operation_texts: 
        equation.insert(i, '*') 
      elif equation[i] == ')' and i != len(equation)-1: 
       if equation[i+1] not in self.operation_texts: 
        equation.insert(i+1, '*') 

     if equation: 
      try: 
       self.labels[0].config(text=str(eval(''.join(equation)))) 
      except ZeroDivisionError: 
       messagebox.showerror("Error", "Zero division error: Your expression has a division by zero") 
      except SyntaxError: 
       messagebox.showerror("Error", "Syntax error: Your expression has incorrect syntax") 

class GUI(Logic): 
    numpad_texts = ('7', '8', '9', '4', '5', '6', '1', '2', '3', '0', '.', 'Equals') 
    operation_texts = ('/', '*', '-', '+', '(', ')') 
    function_texts = ('Delete', 'Back') 

    def __init__(self, master): 
     master.title('Calculator') 

     self.expression = list() 

     self.label_frame = Frame(master) 
     self.label_frame.grid(columnspan=2) 

     self.labels = list() 

     for i in range(2): 
      self.labels.append(Label(self.label_frame)) 
      self.labels[i].grid(row=i, column=0, columnspan=4) 

     self.labels[0].bind("<Button-1>", self.add_answer) 

     self.numpad_frame = Frame(master) 
     self.numpad_frame.grid(row=1, rowspan=2) 

     self.numpad_buttons = list() 

     for i in range(len(self.numpad_texts)): 
      self.numpad_buttons.append(Button(self.numpad_frame, text=self.numpad_texts[i], command=lambda i=i: self.add_digit(self.numpad_texts[i]))) 
      self.numpad_buttons[i].grid(row=i//3, column=i%3) 
      if self.numpad_texts != 11: 
       master.bind(self.numpad_texts[i], self.add_digit) 

     self.numpad_buttons[-1].config(command=self.equals) 

     self.operations_frame = Frame(master) 
     self.operations_frame.grid(row=1, column=1) 

     self.operation_buttons = list() 

     for i in range(len(self.operation_texts)): 
      self.operation_buttons.append(Button(self.operations_frame, text=self.operation_texts[i], command=lambda i=i: self.add_operation(self.operation_texts[i]))) 
      self.operation_buttons[i].grid(row=i//2, column=i%2) 
      master.bind(self.operation_texts[i], self.add_operation) 

     self.functions_frame = Frame(master) 
     self.functions_frame.grid(row=2, column=1) 

     self.function_buttons = list() 

     for i in range(len(self.function_texts)): 
      self.function_buttons.append(Button(self.functions_frame, text=self.function_texts[i])) 
      self.function_buttons[i].grid(row = 0, column=i%2) 

     self.function_buttons[0].config(command=self.delete) 
     self.function_buttons[1].config(command=self.back) 

     master.bind('<Delete>', self.delete) 
     master.bind('<BackSpace>', self.back) 
     master.bind('<Return>', self.equals) 
     master.bind('<Insert>', self.add_answer) 

     messagebox.showinfo("Guide", "Key bindings include: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, ., +, -, *, /, (,), Enter, Backspace, Insert and Delete.") 

if __name__ == '__main__': 
    root = Tk() 
    calculator = GUI(root) 
    root.mainloop() 

Answer 1

Tkinters消息框需要分别输入：

from tkinter import messagebox

然后添加以下为您的绑定信息框的下面那条线：

master.focus_force()

这将焦点移至在用户关闭消息箱和所有绑定之后回到根窗口将继续工作。