Obtain the IP address and determine whether the IP address is in the interval. Obtain the ip address judgment interval.

Obtain the IP address and determine whether the IP address is in the interval. Obtain the ip address judgment interval.

/// <Summary> /// obtain the Client IP /// </summary> /// <returns> </returns> public static string GetClientIpAddress () {var httpContext = HttpContext. current; if (httpContext. request. serverVariables = null) {return null;} var clientIp = httpContext. request. serverVariables ["HTTP_X_FORWARDED_FOR"]? HttpContext. request. serverVariables ["REMOTE_ADDR"]; try {foreach (var hostAddress in Dns. getHostAddresses (clientIp) {if (hostAddress. addressFamily = AddressFamily. interNetwork) {return hostAddress. toString () ;}} foreach (var hostAddress in Dns. getHostAddresses (Dns. getHostName () {if (hostAddress. addressFamily = AddressFamily. interNetwork) {return hostAddress. toString () ;}} catch (Exception ex) {} return clientIp ;} /// <summary> // whether the ip address is in the ip address space // </summary> // <param name = "ip"> </param> /// <param name = "ipSection"> </param> // <returns> </returns> public static Boolean ipExistsInRange (String ip, string ipSection) {ipSection = ipSection. trim (); ip = ip. trim (); int idx = ipSection. indexOf ('-'); String beginIP = ipSection. substring (0, idx); String endIP = ipSection. substring (idx + 1); return getIp2long (beginIP) <= getIp2long (ip) & getIp2long (ip) <= getIp2long (endIP);} public static long getIp2long (String ip) {ip = ip. trim (); String [] ips = ip. split ('. '); long ip2long = 0L; for (int I = 0; I <4; ++ I) {ip2long = ip2long <8 | Int64.Parse (ips [I]);} return ip2long;} public static long getIp2long2 (String ip) {ip = ip. trim (); String [] ips = ip. split ('. '); long ip1 = Int64.Parse (ips [0]); long ip2 = Int64.Parse (ips [1]); long ip3 = Int64.Parse (ips [2]); long ip4 = Int64.Parse (ips [3]); long ip2long = 1L * ip1 * 256*256*256 + ip2 * 256*256 + ip3 * 256 + ip4; return ip2long ;}