using System;
using System.Windows.Forms;

using Microsoft.VisualBasic.ApplicationServices;

namespace SingleInstanceWinFormCsharp
{
    static class Program
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            string[] args = Environment.GetCommandLineArgs();
            SingleInstanceApplication app = new SingleInstanceApplication();
            app.Run(args);
        }

        public class SingleInstanceApplication : WindowsFormsApplicationBase
        {
            public SingleInstanceApplication()
            {
                IsSingleInstance = true;

                StartupNextInstance += my_StartupNextInstance;
            }

            void my_StartupNextInstance(object sender, StartupNextInstanceEventArgs e)
            {
                Form1 form = MainForm as Form1;
            }

            protected override void OnCreateMainForm()
            {
                MainForm = new Form1();
            }
        }
    }
}