C#验证整数

         /**/ /// <summary>
        /// 验证是否是整数
        /// </summary>
        /// <param name="lstr">string</param>
        /// <returns>bool</returns>
         public   static   bool  isNumberR( string  lstr) 
         ... { 
            string pat = @"^(d{1,9}$)";
            Regex r=new Regex(pat,RegexOptions.Compiled);
            Match m=r.Match(lstr);

            if(!m.Success)
            ...{
                return false;
            }
            return true;
        }     


         /**/ /// <summary>
        ///验证是否是整数
        /// </summary>
        /// <param name="str">string</param>        
        /// <returns>bool</returns>
         public   static   bool  IsNum( string  str)
         ... {
            bool flag = true;
            try
            ...{
                Int32.Parse(str);                
            }
            catch(FormatException)
            ...{
                flag = false;
            }
            return flag;
        }