string a="asdfasdfasdf";
            DateTime now = DateTime.Now;
            for (int i = 0; i < 100000000; i++)
            {
                if (a=="123456")
                { }
                else if (a == "asdfasdfasdf")
                { }
            }
            DateTime end1 = DateTime.Now;

            for (int i = 0; i < 100000000; i++)
            { 
                switch (a)
                {
                    case "123456":
                        break;
                    case "asdfasdfasdf":
                        break;
                    default:
                        break;

                }
            }
            DateTime end2 = DateTime.Now;

            System.TimeSpan ifdiff = end1 - now;
            System.TimeSpan swithdiff = end2 - end1;
            MessageBox.Show(ifdiff.Milliseconds.ToString()+"     "+swithdiff.Milliseconds.ToString());