Title: Determine If the Workstation Is Locked
Question: How can I Determine If the Workstation Is Locked?
Answer:
The SwitchDesktop function makes a desktop visible and activates it. This enables the desktop to receive input from the user. The calling process must have DESKTOP_SWITCHDESKTOP access to the desktop for the SwitchDesktop function to succeed.
A call to the OpenDesktop API (using the DESKTOP_SWITCHDESKTOP flag), followed by a call to the SwitchDesktop API (using the handle returned by OpenDesktop) will determine which condition (Locked or not locked) exists (in Windows 2000 or XP),
function IsWorkstationLocked: Boolean;
var
hDesktop: HDESK;
begin
Result := False;
hDesktop := OpenDesktop('default',
0, False,
DESKTOP_SWITCHDESKTOP);
if hDesktop 0 then
begin
Result := not SwitchDesktop(hDesktop);
CloseDesktop(hDesktop);
end;
end;