如何提高这些UPS查询的速度/效率？

Question

在我之前的其他人写了一个程序，需要一堆UPS跟踪＃并查询UPS的状态。问题是，随着时间的推移，这个程序变得越来越复杂。这些查询现在花了太长时间。每个查询大约需要350毫秒，有些页面有近40个查询，每页加载大约需要15秒。

该方法将跟踪＃作为字符串，然后向UPS发出某种xml请求，返回正确的数据，速度非常慢。

以下是代码：

public static List<string> MakeRequest(string tracking)
{
    List<string> res = new List<string>();

    string xmlStringRequest = "<?xml version=\"1.0\"?>" +
                      "<AccessRequest xml:lang=\"en-US\">" +
                      "<AccessLicenseNumber>apilicense</AccessLicenseNumber>" +
                      "<UserId>apiusername</UserId>" +
                      "<Password>apipassword</Password>" +
                      "</AccessRequest>" +
                      "<?xml version=\"1.0\"?>" +
                      "<TrackRequest xml:lang=\"en-US\">" +
                      "<Request>" +
                      "<TransactionReference>" +
                      "<CustomerContext>Your Test Case Summary Description</CustomerContext>" +
                      "<XpciVersion>1.0</XpciVersion>" +
                      "</TransactionReference>" +
                      "<RequestAction>Track</RequestAction>" +
                      "<RequestOption>1</RequestOption>" +
                      "</Request>" +
                      "<TrackingNumber>" + tracking + "</TrackingNumber>" +
                      "</TrackRequest>";

    ASCIIEncoding encodedData = new ASCIIEncoding();
    byte[] byteArray = encodedData.GetBytes(xmlStringRequest);

    //Create Request
    HttpWebRequest wr = (HttpWebRequest)WebRequest.Create("https://onlinetools.ups.com/ups.app/xml/Track");
    wr.Method = "POST";
    wr.KeepAlive = false;

    //wr.ContentType = "application/x-www-form-urlencoded";
    wr.ContentLength = byteArray.Length;
    XmlDocument xmlDoc = new XmlDocument();
    try
    {
        //Send XML
        Stream SendStream = wr.GetRequestStream();
        SendStream.Write(byteArray, 0, byteArray.Length);
        SendStream.Close();

        //Get Response
        WebResponse response = wr.GetResponse();
        Stream responseStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(responseStream);

        //Console.Write(reader.ReadToEnd());

        xmlDoc.LoadXml(reader.ReadToEnd());

        XmlNode nl = xmlDoc.GetElementsByTagName("ResponseStatusCode").Item(0);
        response.Close();

        if (nl.InnerText == "1")
        {
            XmlNode del = xmlDoc.GetElementsByTagName("ActivityLocation").Item(0);
            XmlNodeList act = del.ChildNodes;

            foreach (XmlNode n in act)
            {
                if (n.Name == "Code")
                {
                    res.Add(n.InnerText);
                }
                else if (n.Name == "Description")
                {
                    res.Add(n.InnerText);
                }
                else if (n.Name == "SignedForByName")
                {
                    res.Add(n.InnerText);
                }
                else
                {
                    continue;
                }
            }


            res.Add(xmlDoc.GetElementsByTagName("Date").Item(0).InnerText);
            res.Add(xmlDoc.GetElementsByTagName("Time").Item(0).InnerText);
        }
        else
        {
            res.Add("Tracking Info Not Available");
        }

    }
    catch (Exception ex)
    {
        xmlDoc = null;
    }

    return res;
}

我介绍了代码，看起来花费最长的是这一行：

SendStream.Write(byteArray, 0, byteArray.Length);

是否有一种明显的方法可以提高此查询的速度/效率？我对jSON比对XML更熟悉。