TryParse for Int32, long, byte , and decimal return Boolean Int32.TryParse( s as String, ref i as int32) [VB] Int32.TryParse(String s, out int32 i) [C#] long.TryParse( s as String, ref i as int32) [VB] long.TryParse(String s, out int32 i) [C#] int32.TryParse(s, out i) http://msdn.microsoft.com/zh-tw/library/bb384043.aspx