Powershell script from shortcut to change desktop - powershell

Question

Any ideas and suggestions on why this works when run from w/in PS, but not when run from a shortcut defined as:
%SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe -File "C:\Users\bin\ChangeDesktop.ps1"
Contents of ChangeDesktop.ps1:
set-itemproperty -path "HKCU:Control Panel\Desktop" -name WallPaper -value ""
rundll32.exe user32.dll, UpdatePerUserSystemParameters
If I am in the PS "command prompt" environment the desktop background is automatically removed and refreshed, outside of that I have to manually refresh the desktop to effect the change.
System is Windows Server 2008 R2 - fresh install. Script executionpolicy is set to RemoteSigned, and I don't see any PS errors. I Just don't see the desktop refresh automatically when running from a desktop shortcut.
scratches head

Answer 1

rundll32.exe user32.dll, UpdatePerUserSystemParameters didn't actually change the wallpaper for me on a 2008 x64 box. This does did though... It calls the Win32 API to invoke changing the wallpaper. If you save this as your ChangeDesktop.ps1 script it should work. As it is below it will remove any desktop wallpaper. However if you do want to set one you can edit the last line with the path of a supported image file like this:
[Wallpaper.Setter]::SetWallpaper( 'C:\Wallpaper.bmp', 0 )
The second argument is for the styling:
0: Tile
1: Center
2: Stretch
3: No Change
The script:
Add-Type #"
using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;
namespace Wallpaper
{
public enum Style : int
{
Tile, Center, Stretch, NoChange
}
public class Setter {
public const int SetDesktopWallpaper = 20;
public const int UpdateIniFile = 0x01;
public const int SendWinIniChange = 0x02;
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern int SystemParametersInfo (int uAction, int uParam, string lpvParam, int fuWinIni);
public static void SetWallpaper ( string path, Wallpaper.Style style ) {
SystemParametersInfo( SetDesktopWallpaper, 0, path, UpdateIniFile | SendWinIniChange );
RegistryKey key = Registry.CurrentUser.OpenSubKey("Control Panel\\Desktop", true);
switch( style )
{
case Style.Stretch :
key.SetValue(#"WallpaperStyle", "2") ;
key.SetValue(#"TileWallpaper", "0") ;
break;
case Style.Center :
key.SetValue(#"WallpaperStyle", "1") ;
key.SetValue(#"TileWallpaper", "0") ;
break;
case Style.Tile :
key.SetValue(#"WallpaperStyle", "1") ;
key.SetValue(#"TileWallpaper", "1") ;
break;
case Style.NoChange :
break;
}
key.Close();
}
}
}
"#
[Wallpaper.Setter]::SetWallpaper( '', 0 )
Originally from PoshCode: http://poshcode.org/491

Answer 2

This might sounf weird, but what worked for me was using single quotes instead of double. So it would look like this:
Set-ItemProperty -path "HKCU:Control Panel\Desktop" -name 'wallpaper' -value 'some value'
rundll32.exe user32.dll, UpdatePerUserSystemParameters

Answer 3

This script works wonders. For a domain deployment, we didn't want it to continuously change the background each time a user logs in.
I made the following changes so that it checks to see if the background exists on the computer in the desired location, if it does exist then to exit, if it does not to go ahead with the file copy and set the background.
it first maps the hidden share, copies the file to the desired directory, sets the wallpaper and then disconnects the hidden share. if "X" is already used by your company insert another drive letter. :D
$strFileName="C:\Users\Public\Pictures\background.jpg"
If (Test-Path $strFileName){
# // File exists
Exit-PSSession
}Else{
# // File does not exist
New-PSDrive -Name X -PSProvider Filesystem -Root \\hiddenfileshare\wallpapers
Copy-Item X:\background.jpg C:\Users\Public\Pictures
[Wallpaper.Setter]::SetWallpaper( 'C:\Users\Public\Pictures\background.jpg', 0 )
Remove-PSDrive X
}

Answer 4

The script provided by Andy Arismendi is awesome!
I've used it to make a fun project - set a random wallpaper scraped from the net.
I'm posting it here for anyone interested. Before using it you need to change a few constants at the top of the script source. You also need to download the HtmlAgilityPack.dll library (there are instructions in the script comments).
Enjoy!
P.S. If the wallpaper site I'm using goes down or changes its layout the scraping in the script will go to hell, but nevertheless with my script as an example I bet you'll be able to build another wallpaper scraper.
############## CONSTANTS ##############
# add the library for parsing html - HtmlAgilityPack - download it with nuget from https://www.nuget.org/packages/HtmlAgilityPack
# download nuget command line from https://dist.nuget.org/index.html and install HtmlAgilityPack with "nuget install HtmlAgilityPack" from the cmd
# enter the path to HtmlAgilityPack.dll library used for html parsing
$html_parser_path = "C:\Users\username\Documents\htmlagilitypack\HtmlAgilityPack.1.4.9.5\lib\Net20\HtmlAgilityPack.dll"
# choose where your wallpapers will be downloaded
$wallpaper_dir_path = "C:\Users\username\Pictures\"
# get random wallpaper category from wallpaperscraft.com - the ones below are my favourite categories, edit it if you want to get other categories
<#
you can choose your favorite wallpaper categories from the list below
3D
Abstract
Animals
Anime
Brands
Cars
City
Fantasy
Flowers
Food
Games
Girls
Hi-Tech
Holidays
Macro
Men
Movies
Music
Nature
Other
Space
Sport
Textures
TV Series
Vector
#>
$categories = #("animals","flowers","macro","nature","space")
# I download my wallpapers from the site below - real quality wallpapers
# don't forget to change your resolution - I'm using a 1920x1080 monitor
<#
A list of resolutions to choose from:
1600x1200
1400x1050
1280x1024
1280x960
1152x864
1024x768
3840x2400
3840x2160
3840x1200
2560x1600
2560x1440
2560x1080
2560x1024
2048x1152
1920x1200
1920x1080
1680x1050
1600x900
1440x900
1280x800
1280x720
2160x3840
1440x2560
1366x768
1080x1920
1024x600
960x544
800x1280
800x600
720x1280
540x960
480x854
480x800
400x480
360x640
320x480
320x240
240x400
240x320
2732x2732
2048x2048
1080x1920
1024x1024
750x1334
640x1136
640x960
320x480
1366x768
1920x1080
360x640
1024x768
1600x900
1280x900
1440x900
1280x1024
800x600
1680x1050
2560x1440
320x480
1920x1200
480x800
720x1280
#>
$resolution = "1920x1080" # default resolution
$url = "https://wallpaperscraft.com/catalog/category/$resolution" # category is a placeholder
############## END OF CONSTANT DECLARATIONS ##############
Add-Type #"
using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;
namespace Wallpaper
{
public enum Style : int
{
Tile, Center, Stretch, NoChange
}
public class Setter {
public const int SetDesktopWallpaper = 20;
public const int UpdateIniFile = 0x01;
public const int SendWinIniChange = 0x02;
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern int SystemParametersInfo (int uAction, int uParam, string lpvParam, int fuWinIni);
public static void SetWallpaper ( string path, Wallpaper.Style style ) {
SystemParametersInfo( SetDesktopWallpaper, 0, path, UpdateIniFile | SendWinIniChange );
RegistryKey key = Registry.CurrentUser.OpenSubKey("Control Panel\\Desktop", true);
switch( style )
{
case Style.Stretch :
key.SetValue(#"WallpaperStyle", "2") ;
key.SetValue(#"TileWallpaper", "0") ;
break;
case Style.Center :
key.SetValue(#"WallpaperStyle", "1") ;
key.SetValue(#"TileWallpaper", "0") ;
break;
case Style.Tile :
key.SetValue(#"WallpaperStyle", "1") ;
key.SetValue(#"TileWallpaper", "1") ;
break;
case Style.NoChange :
break;
}
key.Close();
}
}
}
"#
Add-Type -Path $html_parser_path
$rand_index = Get-Random -minimum 0 -maximum $categories.Length
$random_category = $categories[$rand_index]
# replace the placeholder "category" with the random category chosen above
$url = $url -replace "category", $random_category
$doc = New-Object HtmlAgilityPack.HtmlDocument
$doc.LoadHtml((New-Object System.Net.WebClient).DownloadString($url))
# NOTE: the html parser I'm using locates elements by XPath only
$page_links = $doc.DocumentNode.SelectSingleNode("//div[contains(#class, 'pages')]").SelectNodes("a")
# get last page link
$last_page_link = $page_links[$page_links.Count - 1].GetAttributeValue("href", "")
# get last page number
$last_page_number = [regex]::match($last_page_link,'.*page(\d+)').Groups[1].Value
$random_page_number = Get-Random -minimum 0 -maximum $last_page_number
$random_page_addr = ""
# page 1 doesn't add anything to the url
if ($random_page_number -gt 0){
$random_page_addr = "/page$random_page_number"
}
$doc.LoadHtml((New-Object System.Net.WebClient).DownloadString("$url$random_page_addr"))
# get wallpaper divs
$wallpaper_divs = $doc.DocumentNode.SelectNodes("//div[contains(#class, 'wallpaper_pre')]")
$random_wallpaper_div = Get-Random -minimum 0 -maximum 15 # there are 15 wallpapers on a page
# get a sample wallpaper link which has to be substituted later
$sample_wallpaper_link = $wallpaper_divs[$random_wallpaper_div].SelectNodes("a")[0].GetAttributeValue("href", "")
# substitute the above link to get the image link itself
$sample_wallpaper_link = $sample_wallpaper_link -replace "download", "image"
$sample_wallpaper_link = $sample_wallpaper_link -replace "/$resolution", "_$resolution.jpg"
$sample_wallpaper_link = $sample_wallpaper_link -replace "//", "https://"
$wallpaper_image_name = [regex]::match($sample_wallpaper_link,'.*image/(\w+)').Groups[1].Value
$wallpaper_image_name = "$wallpaper_image_name.jpg"
$wc = New-Object System.Net.WebClient
$save_location = "$wallpaper_dir_path$wallpaper_image_name"
$wc.DownloadFile($sample_wallpaper_link, "$save_location")
[Wallpaper.Setter]::SetWallpaper($save_location, 1 )