Creating a background changer in python with ctypes, not working

Question

I\'m working on a simple (I thought) program to set a different desktop background for every day of the week. It runs with no errors but nothing happens. The path to the ima

Answer 1

This is not an answer to your question, but you can generally minify your program and remove redundancy by doing something like this instead:

import time;
import ctypes;
SPI_SETDESKWALLPAPER = 20

wallpapers = [
    r"C:\Users\Owner\Documents\Wallpaper\1.jpg",
    r"C:\Users\Owner\Documents\Wallpaper\2.jpg",
    r"C:\Users\Owner\Documents\Wallpaper\3.jpg",
    r"C:\Users\Owner\Documents\Wallpaper\4.jpg",
    r"C:\Users\Owner\Documents\Wallpaper\5.jpg",
    r"C:\Users\Owner\Documents\Wallpaper\6.jpg",
    r"C:\Users\Owner\Documents\Wallpaper\7.jpg",
]

localtime = time.localtime(time.time())
wkd = localtime[6]
ctypes.windll.user32.SystemParametersInfoA(SPI_SETDESKWALLPAPER, 0, wallpapers[wkd], 0)

Answer 2

I must have read every existing site on this topic and just before giving up, came to this working code (win7 pro 64 bit, python 3.4)

import ctypes
SPI_SETDESKWALLPAPER = 0x14     #which command (20)

SPIF_UPDATEINIFILE   = 0x2 #forces instant update
src = r"D:\Downloads\_wallpapers\3D-graphics_Line_025147_.jpg" #full file location
#in python 3.4 you have to add 'r' before "path\img.jpg"

print(ctypes.windll.user32.SystemParametersInfoW(SPI_SETDESKWALLPAPER, 0, src, SPIF_UPDATEINIFILE))

It uses SystemParametersInfoW instead of SystemParametersInfoA (W instead of A).

Hope it helps you and many others who seem to have similar problems.

Answer 3

If you are using Python 3 you should use ctypes.windll.user32.SystemParametersInfoW instead of ctypes.windll.user32.SystemParametersInfoA(W instead of A as this answer said). Another answer described that because in Python 3 the str type is in form of UTF-16 as wchar_t * in C.

What's more, please minimize the code like this:

import time;
import ctypes;
SPI_SETDESKWALLPAPER = 20

wallpapers = r"C:\Users\Owner\Documents\Wallpaper\%d.jpg"

localtime = time.localtime(time.time())
wkd = localtime[6]
ctypes.windll.user32.SystemParametersInfoW(SPI_SETDESKWALLPAPER, 0, wallpapers%(wkd+1), 0)

Don't Repeat Yourself.