So for an idea for my birthday party I'm setting up a photo booth. I've got software to remotely control the camera and all that, but I need to write a little application to monitor the folder where the pictures get saved and display them.

Here's what I've got so far. The issue is that I don't want to launch a new Windows Photo Viewer process every time the FileSystemWatcher sees a new file, I just want to load the latest image into the current instance of the Windows Photo Viewer (or start a new one if one isn't running).

    class Program
    {
        static void Main(string[] args)
        {
            new Program().StartWatching();
        }

        public void StartWatching()
        {
            FileSystemWatcher incoming = new FileSystemWatcher();
            incoming.Path = @"G:\TempPhotos\";
            incoming.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName;
            incoming.Filter = "*.jpg";

            incoming.Created += new FileSystemEventHandler(ShowImage);

            incoming.EnableRaisingEvents = true;

            Console.WriteLine("Press \'q\' to quit.");
            while (Console.Read() != 'q') ;
        }

        private void ShowImage(object source, FileSystemEventArgs e)
        {
            string s1 = Environment.ExpandEnvironmentVariables("%windir%\\system32\\rundll32.exe ");
            string s2 = Environment.ExpandEnvironmentVariables("%windir%\\system32\\shimgvw.dll,ImageView_Fullscreen " + e.FullPath);

            Process.Start(s1, s2);

            Console.WriteLine("{0} : Image \"{0}\" at {1:t}.", e.ChangeType, e.FullPath, DateTime.Now);
        }
    }

If you don't have a tried and true solution, a simple push in the right direction would be just as valuable. And FYI, this will be running on a 64-bit Windows 7 machine.

Thanks!