时间间隔和倒序排列

倒序排列：

  private static void TestRegex15()
        {
            string a = "289506152200";
            StringBuilder b = new StringBuilder();
            for (int i = a.Length - 2; i >= 0; i = i - 2)
            {
                b.Append(a.Substring(i, 2));
                b.Append(":");
            }
            if (b.Length > 1)
            {
                b.Remove(b.Length - 1, 1);
            }
            Console.Write(b);
        }

 

两个时间的间隔：

  DateTime dtNightEnd = Convert.ToDateTime("2010-6-17 12:00:02");
            System.TimeSpan ts =  DateTime.Now.Subtract(dtNightEnd);
           MessageBox.Show(ts.Hours.ToString());
           MessageBox.Show(ts.Minutes.ToString());
           MessageBox.Show(ts.Seconds.ToString());