如何查看单击哪个tkinter画布形状？

Question

I have a simple program, with some buttons who are not made by Tkinter self. I just made them with canvas.create_rectangle and things like that. But the problem is: The buttons can move. I can do it like this:

if event.x > c.coords(button)[0] and event.y > c.coords(button)[1] \
and event.x < c.coords(button)[2] and event.y < c.coords(button)[3]:
    ::line of code::

But is there a shorter way? Thanks!

Answer 1

You can use tag binding: canvas.tag_bind(<tag>, '<1>', callback) , just replace <tag> by the item id of your button. Here is an example:

import tkinter as tk

def on_click(event):
    print('click')
    canvas.move(button1, 10, 5)

root = tk.Tk()
canvas = tk.Canvas(root)
canvas.pack()

button1 = canvas.create_rectangle(10, 10, 50, 50, fill='red')
canvas.tag_bind(button1, '<1>', on_click)

root.mainloop()

Answer 2

You can use the canvas tag current , which specifies the item under the cursor. From the official tcl/tk documentation:

The tag current is managed automatically by Tk; it applies to the current item, which is the topmost item whose drawn area covers the position of the mouse cursor (different item types interpret this in varying ways; see the individual item type documentation for details). If the mouse is not in the canvas widget or is not over an item, then no item has the current tag.