[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);
           }
       }
   }