C# 分享几个ip的方法吧，包括正则验证ip

/// <summary>
        /// 正规则试验IP地址
        /// </summary>
        /// <param name="IP"></param>
        /// <returns></returns>
        public bool IPCheck(string IP)
        {
            string num = "(25[0-5]|2[0-4]\\d|[0-1]\\d{2}|[1-9]?\\d)";
            return Regex.IsMatch(IP, ("^" + num + "\\." + num + "\\." + num + "\\." + num + "[        DISCUZ_CODE_0        ]quot;));
        }
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            System.Environment.Exit(0);
        }
        #region ip转换
        /// <summary>
        /// ip转成long
        /// </summary>
        /// <param name="ip"></param>
        /// <returns></returns>
        public static long IpToInt(string ip)
        {
            char[] separator = new char[] { '.' };
            string[] items = ip.Split(separator);
            return long.Parse(items[0]) << 24
                    | long.Parse(items[1]) << 16
                    | long.Parse(items[2]) << 8
                    | long.Parse(items[3]);
        }
        /// <summary>
        /// long转成ip
        /// </summary>
        /// <param name="ipInt"></param>
        /// <returns></returns>
        public static string IntToIp(long ipInt)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append((ipInt >> 24) & 0xFF).Append(".");
            sb.Append((ipInt >> 16) & 0xFF).Append(".");
            sb.Append((ipInt >> 8) & 0xFF).Append(".");
            sb.Append(ipInt & 0xFF);
            return sb.ToString();
        }
        #endregion