private static void Application_Idle(object sender, EventArgs e)
 {
     Application.Idle -= new EventHandler(Application_Idle);
     if (applicationContext.MainForm == null)
     {
         MESMainForm mainForm = new MESMainForm();
         applicationContext.MainForm = mainForm;
         //初始化
         mainForm.InitMain();
         WelcomeForm welcomeForm = applicationContext.Tag as WelcomeForm;
         mainForm.Show();
         welcomeForm.Close();
     }
 }
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            //Application.Run(new MESMainForm());
            //return;
            WelcomeForm welcomeForm = new WelcomeForm();

            welcomeForm.Show();
            applicationContext     = new ApplicationContext();
            applicationContext.Tag = welcomeForm;
            Application.Idle      += Application_Idle;
            Application.Run(applicationContext);
        }