powershell/modules/Azure.Arc.Jumpstart.Common/source/Public/Set-JSDesktopBackground.ps1

function Set-JSDesktopBackground {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [string]$ImagePath
    )

$code = @'
    using System.Runtime.InteropServices;
    namespace Win32{

        public class Wallpaper{
            [DllImport("user32.dll", CharSet=CharSet.Auto)]
            static extern int SystemParametersInfo (int uAction , int uParam , string lpvParam , int fuWinIni) ;

            public static void SetWallpaper(string thePath){
                SystemParametersInfo(20,0,thePath,3);
            }
        }
    }
'@

Add-Type $code
[Win32.Wallpaper]::SetWallpaper($ImagePath)

}