Hi all,


I've been banging my head against this one for the last several hours, so I'll buy a beer for the man or woman who helps me figure it out! J


Quite simply, all I'm trying to do is programmatically toggle the "Lock the Taskbar" setting. However, I can't get the taskbar to refresh itself after I toggle the setting (I have to hover my mouse over the taskbar and press F5).


I thought I could do it in two steps:


1. Set the pertinent registry value to 1 (not locked) or 0 (locked).

2. Then send the HWND_BROADCAST message to all windows using the SendMessageTimeout() function.


Here's the code:


use Win32::TieRegistry( Delimiter=>"/" );

$Registry->{"CUser/Software/Microsoft/Windows/CurrentVersion/Explorer/Advanced//TaskbarSizeMove"} = [ pack("L",1), "REG_DWORD" ];


use Win32::API;

use constant HWND_BROADCAST => 65535;

use constant WM_SETTINGCHANGE => 26;

my $SendMessageTimeout = new Win32::API('user32', 'SendMessageTimeout', 'NNNNNNN', 'N');

$SendMessageTimeout->Call(HWND_BROADCAST, WM_SETTINGCHANGE, 0, "Windows", SMTO_BLOCK, 1000, undef);


This code almost works. The setting is toggled in the registry and the desktop refreshes itself...but the taskbar stays the same unless I manually refresh it.


Since broadcasting the message didn't work, I decided to get the taskbar handle and send the message only to it:


use Win32::GUI();

my $taskbar = Win32::GUI::FindWindow("Shell_TrayWnd", "");

Win32::GUI::SendMessage($taskbar, WM_SETTINGCHANGE, undef, "HKEY_CURRENT_USER");


This doesn't work either, so I decided to call invalidateRect() on the taskbar:


Win32::GUI::InvalidateRect($taskbar, 0, 0, Win32::GUI::Width($taskbar), Win32::GUI::Height($taskbar), 1);


Still nothing, so I tried calling Hide() and Show() on the taskbar



sleep(1); # To make sure it's hiding



It hides and shows, but the setting still isn't taking effect! I get the feeling I’m going about this all wrong, but I’m running out of ideas (and I've searched all over MSDN).


Any ideas?