using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace demo
{
    static class Program
    {
        public static ApplicationContext app; //这里
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            app = new ApplicationContext(new frmStart());
            Application.Run(app);
        }
    }
}

        private void frmStart_MouseClick(object sender, MouseEventArgs e)
        {
            frmMain frm = new frmMain();
            Program.app.MainForm = frm;
            frm.Show();
            this.Close();
        }