獲取Ip地址，程式碼如下：

public static string GetIp()
{
   string ip = string.Empty;
   HttpContext context = HttpContext.Current;
   if (context != null)
   {
      HttpRequest request = context.Request;
      ip = request.Headers["HTTP_X_FORWARDED_FOR"];//微信相關特殊處理，@劉俊
      if (string.IsNullOrEmpty(ip) || (ip.ToLower() == "unknown"))
      {
          ip = request.ServerVariables["HTTP_X_FORWARDED_FOR"];
          if (string.IsNullOrEmpty(ip) || (ip.ToLower() == "unknown"))
          {
              ip = request.ServerVariables["HTTP_X_REAL_IP"];
              if (string.IsNullOrEmpty(ip))
              {
                   ip = request.ServerVariables["REMOTE_ADDR"];
               }
           }
       }
    }
    return GetShortIp(ip);
}