c#获得客户端IP地址

#region  GetIp   获得IP地址
    public static string GetIp()
    {
        if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
        {
            return System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].
                        Split(new char[] { ',' })[0];
        }
        else
        {
            return System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
        }
    }
    #endregion