//方法一 HttpContext.Current.Request.UserHostAddress;
//方法二 HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
//方法三 string strHostName = System.Net.Dns.GetHostName(); string clientIPAddress = System.Net.Dns.GetHostAddresses(strHostName).GetValue(0).ToString();
//方法四(无视代理) HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];