DataTime dt = new DataTime (); // dt 为时间 DataTime 对象
Dt.ToString (); // 2005-11-5 13:47:04
Dt.Addyears (1) .ToString (); // 2006-11-5 13:47:04
Dt.Adddays (1.1) .ToString (); // 2005-11-6 16:11:04
Dt.Addhours (1.1) .ToString (); // 2005-11-5 14:53:04
Dt.Addmilliseconds (1.1) .ToString (); // 2005-11-5 13:47:04
Dt.Addmonths (1) .ToString (); // 2005-12-5 13:47:04
Dt.AddSeconds (1.1) .ToString (); // 2005-11-5 13:47:05
Dt.Addminutes (1.1) .ToString (); // 2005-11-5 13:48:10
Dt.Addticks (1000) .ToString (); // 2005-11-5 13:47:04