Tkinter-Schlüssel funktioniert nicht nach Meldungsfeld

Question

Ich arbeite an einem Taschenrechner und ich habe ein Problem in Bezug auf meine Schlüssel-Bindungen aufgetreten. Am Ende der Einführung meiner GUI-Klasse wird ein Meldungsfeld erstellt, das die Bindungen an den Benutzer erläutert.

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

Ironischerweise bewirkt, dass alle der Bindungen nicht reagieren, bis das Meldungsfeld geschlossen und das tkinter Fenster abgewählt wird dann wieder angewählt. Die Bindungen sind wie folgt codiert:

Ich habe versucht, focus_set() zu verwenden, aber es hilft nicht. Was kann ich tun, damit meine Tastaturbindungen sofort reagieren, nachdem das Meldungsfeld geschlossen wurde?

Hier ist die Gesamtheit meines Codes für Kontext.

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 messagebox muss separat importiert werden:

from tkinter import messagebox

Dann die folgende unterhalb der Linie für Ihre Bindungen messagebox hinzufügen:

master.focus_force()

Dies wird den Fokus Zurück zum Hauptfenster, nachdem der Benutzer die Nachrichtenbox und alle Ihre Bindungen geschlossen hat wird weiter arbeiten.