[C#] 單一化執行

有的時候希望程式只單一執行，可以參考以下的程式

如果你跟我一樣是一個需要登入的系統
用下面的方法會在開一次登入視窗
如果想要直接執行主視窗，可以用兩種方法

1. 起始的class為主視窗，這個方法我不太會
   會知道這個方法是公司同事這樣寫

2. 起始的class為登入視窗，加上已經登入與否的判斷式在

public partial class Login : Form
{ 
   [STAThread]
    static void Main()
    {
        try
        {
            //Application.Run(new Login());
            string[] args = Environment.GetCommandLineArgs();
            SingleInstanceController controller = new SingleInstanceController();
            controller.Run(args);
        }
        catch
        {
        }
    }

    public delegate void ProcessParametersDelegate(object sender, string[] args);

    public void ProcessParameters(object sender, string[] args)
    {
            this.Visible = true;
            this.TopMost = true;
            this.TopMost = false;
    }


    class SingleInstanceController : WindowsFormsApplicationBase
    {
        public SingleInstanceController()
        {
            // Make this a single-instance application
            this.IsSingleInstance = true;
            this.EnableVisualStyles = true;

            // There are some other things available in the VB application model, for
            // instance the shutdown style:
            this.ShutdownStyle = Microsoft.VisualBasic.ApplicationServices.ShutdownMode.AfterMainFormCloses;

            // Add StartupNextInstance handler
            this.StartupNextInstance += new StartupNextInstanceEventHandler(this.SIApp_StartupNextInstance);
        }

        /// <summary>
        /// We are responsible for creating the application's main form in this override.
        /// </summary>
        protected override void OnCreateMainForm()
        {
            // Instantiate your main application form
            // Create an instance of the main form and set it in the application; 
            // but don't try to run it.
            this.MainForm = new Login();

            // We want to pass along the command-line arguments to this first instance
            Random randNum = new Random();
        }

        /// <summary>
        /// This is called for additional instances. The application model will call this 
        /// function, and terminate the additional instance when this returns.
        /// </summary>
        /// <param name="eventArgs"></param>
        protected void SIApp_StartupNextInstance(object sender, StartupNextInstanceEventArgs eventArgs)
        {
            // Here you get the control when any other instance is 
            // invoked apart from the first one. 
            // You have args here in e.CommandLine.

            // You custom code which should be run on other instances

            // Copy the arguments to a string array
            string[] args = new string[eventArgs.CommandLine.Count];
            eventArgs.CommandLine.CopyTo(args, 0);

            // Create an argument array for the Invoke method
            object[] parameters = new object[2];
            parameters[0] = this.MainForm;
            parameters[1] = args;

            // Need to use invoke to b/c this is being called from another thread.
            this.MainForm.Invoke(new Login.ProcessParametersDelegate(((Login)this.MainForm).ProcessParameters), parameters);
        }
    }
}