1
Extra Credit Assignment – C# Screen Saver
GUI Programming
%1 added to final grade
A Windows screen saver is simply a Windows application that displays either an options dialog box, a preview
screen, or a full-screen window, depending on the command line argument it receives. Windows screen savers
have a .scr extension and are typically stored in the Windows system directory.
Argument Action
/c Configuration mode
/p Preview mode
/s Full-screen mode
Your program can determine which mode your program is to execute by examining the command line
parameters in Main:
static void Main()
{
string[] cmdList = Environment.CommandLine.Split(' ');
// First command-line param is the exe name, second param is the mode
if (cmdList.Length >= 2) {
if (cmdList[1].IndexOf("/c") >= 0) { // Configuration mode
Application.Run(new OptionsForm());
return;
}
parentHwnd = IntPtr.Zero;
if (cmdList[1] == "/p") { // Preview mode
previewMode = true;
// Handle to preview dialog box is next command-line param
parentHwnd = (IntPtr) uint.Parse(cmdList[2]);
}
}
Application.Run(new ScreenSaverForm());
}
The parentHwnd will be used in preview mode and is discussed in the preview mode section. The
ScreenSaverForm is a Windows Form that will need to fill the entire screen. This is done by setting the
ScreenSaverForm’s WindowState property to Maximized and FormBorderStyle to None. The OptionsForm is
just a Windows Form that looks like a typical dialog box for setting properties of the screen saver.
Configuration Mode
In configuration mode, the screen saver should launch a dialog
box that allows the user to control the appearance and settings of
the screen saver. Typically these settings are stored in the
Windows Registry. The Registry is a hierarchical repository of
information used by Windows and applications for storing various
types of configuration data.
The following code segment shows how information can be
stored in and retrieved from the Registry:
