c# - 从 XML 中的最新日期时间戳获取 xmlnode

Question

我正在尝试从 XML 文件中获取 XMLNODE“Price”，XML 本身就很大，并且其中有很多很多“Row”元素。我试图通过最新的“transactionDateTime”获取“Price”节点，因为它有时间戳，但我无法让它工作。

XmlDocument xdocoA = new XmlDocument();
xdocoA.Load(Transation);
XmlNodeList ndlistA = xdocoA.SelectNodes("/eveapi/result/rowset/row[@transactionDateTime]");
foreach (XmlNode xmlnodeA in ndlistA)
{
    LastTN.Text = xmlnodeA.Attributes["price"].InnerText;                               
}

XML 文件:

<eveapi version="2"> 
  <currentTime>2016-02-01 22:48:26</currentTime>  
  <result> 
    <rowset name="transactions" key="transactionID" columns="transactionDateTime,transactionID,quantity,typeName,typeID,price,clientID,clientName,stationID,stationName,transactionType,transactionFor,journalTransactionID,clientTypeID"> 
      <row transactionDateTime="2016-01-31 23:10:57" transactionID="4212499228" quantity="12" typeName="Spodumain Mining Crystal II" typeID="18624" price="900000.00" clientID="94420021" clientName="Gayle Rowen" stationID="61000400" stationName="4F6-VZ XI - Limited Sense" transactionType="buy" transactionFor="personal" journalTransactionID="12205145551" clientTypeID="1373"/>  
      <row transactionDateTime="2016-01-30 17:52:03" transactionID="4210791656" quantity="1" typeName="Small Polycarbon Engine Housing I" typeID="31177" price="500000.00" clientID="95987816" clientName="Lash Wolfram" stationID="61000575" stationName="6-8QLA V - Perrigen Falls Trade Hub" transactionType="buy" transactionFor="personal" journalTransactionID="12198662373" clientTypeID="1376"/>
      <row transactionDateTime="2016-01-30 17:50:44" transactionID="4210790391" quantity="1" typeName="BZ-5 Neutralizing Spatial Destabilizer ECM" typeID="19946" price="549999.99" clientID="920370728" clientName="Missniggins" stationID="61000884" stationName="OP7-BP V - Ivy Towers" transactionType="buy" transactionFor="personal" journalTransactionID="12198656389" clientTypeID="1377"/> 
    </rowset> 
  </result>  
  <cachedUntil>2016-02-01 23:15:21</cachedUntil> 
</eveapi>

Please remember this XML is big and this is just a cut down version.

Answer 1

XElement xml = XElement.Load("dat.xml");

var mostRecentPrice = xml.Descendants("row")
                         .OrderByDescending(r => DateTime.Parse(r.Attribute("transactionDateTime").Value))
                         .First().Attribute("price").Value;

如果行是升序的，您还可以按它们的事务 ID 对行进行排序:

var mostRecentPrice = xml.Descendants("row")
                         .OrderByDescending(r => r.Attribute("transactionID").Value)
                         .First().Attribute("price").Value;