C#获取IP地址

  if(System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"]!=null)
   {
    UserIP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
   }
   else
   {
    UserIP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();
   }