在Tkinter的其他画布上提升画布

Question

I have created number of canvases, and they overlap. I would like to bring a particular canvas to the front.

I don't seem to find a way to do it. The lift method does not seem to work, eg

import tkinter as Tk
w=tk.Tk()
a=tk.Canvas(w,width=20, height=30)
a.place(x=20, y=30)
b=tk.Canvas(w,width=20, height=30)
b.place(x=25, y=35)
w.lift(b)             # try to bring b to the front, but nothing happens

Answer 1

Your canvases are there, the problem is, their color is the same as the rest of the window. You can add background colors to differentiate them.

To change stacking orders on widget level, you should use Tkinter.Misc class.

import tkinter as tk #fixed typo in here
w=tk.Tk()
a=tk.Canvas(w,width=20, height=30, bg="red")
a.place(x=20, y=30)
b=tk.Canvas(w,width=20, height=30, bg="blue")
b.place(x=25, y=35)
tk.Misc.lift(a)
w.mainloop() #even if some IDEs adds mainloop, it's always better to add it explicitly

Answer 2

The problem you are having is because you are choosing to use a Canvas . Canvases have a lift method that overrides the default lift function. The lift method of the canvas is for lifting something drawn on the canvas rather than the canvas itself. If you had chosen to use a frame rather than a canvas, your code would have worked.

You can use the lift method that is part of the Misc library in the case of using a canvas:

tk.Misc.lift(a)