Python Tkinter Canvas

Python GUI Programming

The Python Tkinter Canvas widget is like the canvas in HTML5; it is used for drawing. You can place graphics, text, widgets, or frames on the canvas.

Syntax

The syntax format is as follows:

w = Canvas ( master, option=value, ... )

  • master: The parent container of the button.

  • options: Optional items, i.e., the configurable properties of the button. These options can be set in the form of key = value, separated by commas.

No. Option & Description
1

bd

Border width, in pixels, default is 2 pixels.
2

bg

Background color
3

confine

If true (default), the canvas cannot be scrolled outside the scrollable area.
4

cursor

Cursor shape setting, such as arrow, circle, cross, plus, etc.
5

height

Height
6

highlightcolor

The color to highlight
7

relief

Border style, optional values are FLAT, SUNKEN, RAISED, GROOVE, RIDGE. Default is FLAT.
8

scrollregion

A tuple (w, n, e, s) that defines the maximum scrollable area of the canvas, where w is the left side, n is the top, e is the right side, and s is the bottom.
9

width

The size of the canvas on the X coordinate axis.
10

xscrollincrement

The value used for horizontal scrolling requests.
11

xscrollcommand

Horizontal scrollbar; if the canvas is scrollable, this attribute is the .set() method of the horizontal scrollbar.
12

yscrollincrement

Similar to xscrollincrement, but in the vertical direction.
13

yscrollcommand

Vertical scrollbar; if the canvas is scrollable, this attribute is the .set() method of the vertical scrollbar.

The Canvas widget supports the following standard options:

arc − Create an arc

coord = 10, 50, 240, 210
arc = canvas.create_arc(coord, start=0, extent=150, fill="blue")

image − Create an image

filename = PhotoImage(file = "sunshine.gif")
image = canvas.create_image(50, 50, anchor=NE, image=filename)

line − Create a line

line = canvas.create_line(x0, y0, x1, y1, ..., xn, yn, options)

oval − Create an oval

oval = canvas.create_oval(x0, y0, x1, y1, options)

polygon − Create a polygon with at least three vertices

oval = canvas.create_polygon(x0, y0, x1, y1,...xn, yn, options)

Example

In the example, clicking the button will display a message:

Example

#!/usr/bin/python # -*- coding: UTF-8 -*- import Tkinter import tkMessageBox # -*- coding: cp936 -*- # Create a rectangle and specify the canvas color as white from Tkinter import * root = Tk() # Create a Canvas and set its background color to white cv = Canvas(root,bg = 'white') # Create a rectangle with coordinates (10,10,110,110) cv.create_rectangle(10,10,110,110) cv.pack() root.mainloop() # For clarity, set the background color to white to distinguish it from root top.mainloop()

The test output is as follows:

Python GUI Programming

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