[C#]判断是否是合法的IP4,IP6地址

判断一个字符串如果没有端口的话，利用IPAddress.TryParse很好判断，那么有端口怎么判断呢，正则表达式？还是其他方式？

关键代码：

        /// <summary>
        /// 判断是否是合法的IP4,IP6地址
        /// </summary>
        /// <param name="ip">需要判断的字符串</param>
        /// <returns>合法则返回host部分，若不合法则返回空</returns>
        public static string GetIPAddress(string ip)
        {
            string _ipAddress = string.Empty;
            if (!string.IsNullOrEmpty(ip))
            {
                UriHostNameType _hostType = Uri.CheckHostName(ip);
                if (_hostType == UriHostNameType.Unknown)//譬如 "192.168.1.1:8060"或者[2001:0DB8:02de::0e13]:9010
                {
                    Uri _url;
                    if (Uri.TryCreate(string.Format("http://{0}", ip), UriKind.Absolute, out _url))
                    {
                        _ipAddress = IPAddressTryParse(_url.Host);
                    }
                }
                else if (_hostType == UriHostNameType.IPv4 || _hostType == UriHostNameType.IPv6)
                {
                    _ipAddress = IPAddressTryParse(ip);
                }
            }
            return _ipAddress;
        }
        private static string IPAddressTryParse(string ip)
        {
            string _ipAddress = string.Empty;
            IPAddress _ipAdr;
            if (IPAddress.TryParse(ip, out _ipAdr))
            {
                _ipAddress = _ipAdr.ToString();
            }
            return _ipAddress;
        }

单元测试：

        [TestMethod()]
        public void GetIPAddressTest()
        {
            string _ip4Address1 = "192.168.1.1";
            string _expected1 = "192.168.1.1";
            string _actual1 = NetWorkToolV2.GetIPAddress(_ip4Address1);
            Assert.AreEqual(_expected1, _actual1);

            string _ip4Address2 = "192.168.1.1:8060";
            string _expected2 = "192.168.1.1";
            string _actual2 = NetWorkToolV2.GetIPAddress(_ip4Address2);
            Assert.AreEqual(_expected2, _actual2);

            string _ip6Address3 = "2001:0DB8:02de::0e13";
            string _expected3 = "2001:DB8:2de::e13";
            string _actual3 = NetWorkToolV2.GetIPAddress(_ip6Address3);
            Assert.AreEqual(_expected3, _actual3,true);

            string _ip6Address4 = "[2001:0DB8:2de::e13]:9010";
            string _expected4 = "2001:DB8:2de::e13";
            string _actual4 = NetWorkToolV2.GetIPAddress(_ip6Address4);
            Assert.AreEqual(_expected4, _actual4, true);

            string _ipAddress5 = "erroriptest";
            string _expected5 = string.Empty;
            string _actual5 = NetWorkToolV2.GetIPAddress(_ipAddress5);
            Assert.AreEqual(_expected5, _actual5);

        }

测试结果：

希望有所帮助！