C#保存登录用户名供其他页面调用

static class Program
    {
        public static string loginid = "";
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Login());
            
        }
    }

Program.loginid = this.username.Text;

string loginid = Program.loginid;