C#下的IP2Long

C#下的IP2Long
     public ulong iptolong(string ip)
     {
         string[] cip = ip.Trim().Split('.');
         string[] aip = new string[4];
         cip.CopyTo(aip,0);
         if (cip.Length < 3)
         {
             for (int i = 3;i>cip.Length; i--)
             {
                 aip[i] = "0";
             }
         }
         uint[] iip = new uint[4];
         Regex reg=new Regex(@"\d+");
         for (int x = 0; x < aip.Length; x++)
         {
             if (reg.IsMatch(aip[x]))
                 iip[x] = Convert.ToUInt32(aip[x]);
             else
                 iip[x] = 0;
         }
         ulong uip = Convert.ToUInt64(256 * 256 * 256 * iip[0] + 256 * 256 * iip[1] + 256 * iip[2] + iip[3]);
         return uip;
     }