ScreensaverStars/ScreenSaver/Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace ScreenSaver
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main(string[] args)
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            if (args.Length > 0)
            {
                string firstArgument = args[0].ToLower().Trim();
                string secondArgument = null;

                // Handle cases where arguments are separated by colon. 
                // Examples: /c:1234567 or /P:1234567
                if (firstArgument.Length > 2)
                {
                    secondArgument = firstArgument.Substring(3).Trim();
                    firstArgument = firstArgument.Substring(0, 2);
                }
                else if (args.Length > 1)
                    secondArgument = args[1];
                
                if (firstArgument == "/c")           // Configuration mode
                {
                    MessageBox.Show("There is no configuration for this screensaver");
                }
                else if (firstArgument == "/p")      // Preview mode
                {
                    if (secondArgument == null)
                    {
                        MessageBox.Show("Sorry, but the expected window handle was not provided.",
                            "ScreenSaver", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                        return;
                    }
                    
                    IntPtr previewWndHandle = new IntPtr(long.Parse(secondArgument));
                    Application.Run(new ScreenSaverForm(previewWndHandle));
                }
                else if (firstArgument == "/s")      // Full-screen mode
                {
                    ShowScreenSaver();
                    Application.Run();
                }  
                else    // Undefined argument
                {
                    MessageBox.Show("Sorry, but the command line argument \"" + firstArgument +
                        "\" is not valid.", "ScreenSaver",
                        MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                }
            }
            else    // No arguments - treat like /c
            {
                MessageBox.Show("There is no configuration for this screensaver");
            }            
        }

        /// <summary>
        /// Display the form on each of the computer's monitors.
        /// </summary>
        static void ShowScreenSaver()
        {
           
            int height = 0;
            int width = 0;
            foreach (var screen in System.Windows.Forms.Screen.AllScreens)
            {
                //take smallest height
                height = screen.Bounds.Height;
                width += screen.Bounds.Width;
            }            

            ScreenSaverForm screensaver = new ScreenSaverForm(new System.Drawing.Rectangle(Screen.AllScreens[0].Bounds.X, Screen.AllScreens[0].Bounds.Y, width, height));
            screensaver.Show();
            
        }
    }
}