如何通过新窗口更改 tkinter 画布的大小？

Question

So I have one Tkinter screen that has a canvas. I want to change the size of the canvas by creating a new window that has entry widgets. So I created a new screen and added 2 entry widgets. I want to get the value from those widgets and based on that...it should change the size of the canvas. I tried to do this for an hour, but no luck. Please assist me.

Here is my code

from tkinter import *
# create root window 
root = Tk()

# Create Canvas
canvas = Canvas(root, width=50, height=50)

# Create an additional window (the one that is used to enter the new geometry)
dialog = Toplevel(root)

# Add entry widgets for width and height to the new window
width_entry = tk.Entry(dialog)
height_entry = tk.Entry(dialog)

# Add a button to the new window that applies the given width and height 
apply_button = Button(dialog, text = 'Apply geometry', command = lambda: canvas.geometry(width_entry.get()+'x'+height_entry.get()))

# Its not possible to get the geometry of a canvas in tkinter...so how do I change the size.

# display the entry boxes and button
width_entry.pack()
height_entry.pack()
apply_button.pack()

# start the tk mainloop
root.mainloop()

Please Assist me

Answer 1

The command you are looking for is canvas.config

Here, I have adjusted the given code:

import tkinter as tk
# create root window 
root = tk.Tk()

# Create Canvas
canvas = tk.Canvas(root, width=50, height=50)
canvas.pack()

# Create an additional window (the one that is used to enter the new geometry)
dialog = tk.Toplevel(root)

# Add entry widgets for width and height to the new window
width_entry = tk.Entry(dialog)
height_entry = tk.Entry(dialog)

# Add a button to the new window that applies the given width and height 
apply_button = tk.Button(dialog, text = 'Apply geometry', command = lambda: canvas.config(width=width_entry.get(), height=height_entry.get()))


# display the entry boxes and button
width_entry.pack()
height_entry.pack()
apply_button.pack()

# start the tk mainloop
root.mainloop()

I also changed a couple other things:

You imported * from tkinter, but for some items you still led with tk. ; I changed them all to match that and switched the import to match as well. (You could still use *, but then just don't have the leading tk. s.)

The canvas was never packed so you could never see what was going on there.

One more suggestion, that line where you make the button is really long. Maybe make a function that does what the lambda does and assign its command to that function instead of a lambda. You can probably see that a line that long is even hard to read here much less if someone (maybe a future version of yourself) was to try to read your code, and edit it or make sense of it. Generally, try to keep all lines down to 80 characters.

Let us know if you have any more questions etc.