_tkinter.TclError: nom de la commande non valide » 0,14574424"

Question

Je reçois l'erreur suivante:

_tkinter.TclError: invalid command name “.14574424”

Je ne suis pas en mesure de comprendre l'erreur. Qu'est-ce que je fais mal?

# Import tkinter 
from tkinter import * 

class AnimationDemo: 
    def __init__(self): 
     window = Tk()  # Create a window 
     window.title("Animation Demo")  # Set a title 

     width = 250   # Width of the canvas 
     canvas = Canvas(window, bg = "white", width = 250, height = 50) 
     canvas.pack() 

     x = 0   # Starting x position 
     canvas.create_text(x, 30, text = "Message moving?", tags = "text") 

     dx = 3 
     while True: 
      canvas.move("text", dx, 0)  # Move text dx unit 
      canvas.after(100)   # Sleep for 100 milliseconds 
      canvas.update()   # Update canvas 
      if x < width: 
       x += dx   # Get the current position for string 
      else: 
       x = 0  # Reset string position to the beginning 
       canvas.delete("text") 
       # Redraw text at the beginning 
       canvas.create_text(x, 30, text = "Message moving?", tags = "text") 
     window.mainloop()  # Create an event loop 

AnimationDemo()  # Create GUI 

Answer 1

Comme mentionné par Bryan, au lieu d'utiliser une boucle while, essayez d'animer votre texte directement avec la méthode .after():

import tkinter as tk 

class AnimationDemo: 
    def __init__(self): 
     self.window = tk.Tk() 
     self.window.title("Animation Demo") 

     # Create a canvas 
     self.width = 250 
     self.canvas = tk.Canvas(self.window, bg="white", width=self.width, 
          height=50) 
     self.canvas.pack() 

     # Create a text on the canvas 
     self.x = 0 
     self.canvas.create_text(self.x, 30, text = "Message moving?", tags="text") 
     self.dx = 3 

     # Start animation & launch GUI 
     self.animate_text() 
     self.window.mainloop() 

    def animate_text(self): 
     # Move text dx unit 
     self.canvas.move("text", self.dx, 0) 
     if self.x < self.width: 
      # Get the current position for string 
      self.x += self.dx 
     else: 
      # Reset string position to the beginning 
      self.x = 0 
      self.canvas.delete("text") 
      self.canvas.create_text(self.x, 30, text = "Message moving?", tags="text") 
     self.window.after(100, self.animate_text) 

# Create GUI 
AnimationDemo()