Title: Invoke Windows Screen Saver in Code
Question: How to display/invoke the Windows screen saver programatically
Answer:
There are two ways:
The first which is the neatest solution is to use the WinAPI call
PostMessage(GetDesktopWindow, WM_SYSCOMMAND, SC_SCREENSAVE, 0)
The second involves running the program file for the screen saver which has a .SCR extension. See running other applications elsewhere for this. This method however does not invoke any password security if set on the screen saver.
I wanted a tiny app that I could click to start my screen saver and invoke password security (effectively locking my desktop [without Ctrl-Alt-Del] with my screen saver running) and thus created the following .dpr file:
program SaveScrn;
uses
Forms,
Windows,
Messages;
{$R *.RES}
var
b: Bool;
begin
Application.Initialize;
{ 1st check that a screen saver exists}
if (SystemParametersInfo(SPI_GETSCREENSAVEACTIVE, 0, @b, 0)
and (b) then
begin
{ Invoke Screen saver}
PostMessage(GetDesktopWindow, WM_SYSCOMMAND, SC_SCREENSAVE, 0);
end;
Application.Terminate;
end.
Now I just run the application and my desktop is safe from prying eyes.