C#怎么获取留言人IP

using System.Net;

string ipStr = Dns.GetHostEntry(Dns.GetHostName()).AddressList[0].ToString();// ip地址

www.ruigongye.com

Request.UserHostAddress
就是访问者的ip

string ip = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (null == ip || ip == String.Empty)
{
ip = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
}

if (null == ip || ip == String.Empty)
{
ip = System.Web.HttpContext.Current.Request.UserHostAddress;
}

string ip = "";
if (Context.Request.ServerVariables["HTTP_VIA"] != null)
{
ip = Context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"]