add ep refresh for dark mode toggle (#2732)

functions/private/Invoke-WinUtilDarkMode.ps1

@@ -21,6 +21,7 @@ Function Invoke-WinUtilDarkMode {
         $Path = "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize"
         Set-ItemProperty -Path $Path -Name AppsUseLightTheme -Value $DarkMoveValue
         Set-ItemProperty -Path $Path -Name SystemUsesLightTheme -Value $DarkMoveValue
+        Invoke-WinUtilExplorerRefresh
     } catch [System.Security.SecurityException] {
         Write-Warning "Unable to set $Path\$Name to $Value due to a Security Exception"
     } catch [System.Management.Automation.ItemNotFoundException] {

functions/private/Invoke-WinUtilExplorerRefresh.ps1

@@ -0,0 +1,33 @@
+function Invoke-WinUtilExplorerRefresh {
+    <#
+    .SYNOPSIS
+        Refreshes the Windows Explorer
+    #>
+
+    Invoke-WPFRunspace -DebugPreference $DebugPreference -ScriptBlock {
+        # Send the WM_SETTINGCHANGE message to all windows
+        Add-Type -TypeDefinition @"
+using System;
+using System.Runtime.InteropServices;
+public class Win32 {
+    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
+    public static extern IntPtr SendMessageTimeout(
+        IntPtr hWnd,
+        uint Msg,
+        IntPtr wParam,
+        string lParam,
+        uint fuFlags,
+        uint uTimeout,
+        out IntPtr lpdwResult);
+}
+"@
+
+        $HWND_BROADCAST = [IntPtr]0xffff
+        $WM_SETTINGCHANGE = 0x1A
+        $SMTO_ABORTIFHUNG = 0x2
+        $timeout = 100
+
+        # Send the broadcast message to all windows
+        [Win32]::SendMessageTimeout($HWND_BROADCAST, $WM_SETTINGCHANGE, [IntPtr]::Zero, "ImmersiveColorSet", $SMTO_ABORTIFHUNG, $timeout, [ref]([IntPtr]::Zero))
+    }
+}