XMLDocument选择

Question

我拥有的XML文档格式如下：

<response>
   <forecast>
      <txt_forecast>
         <forecastdays>
            <forecastday>
               <period>0</period>
               <fctext>Sunny</fctext>
            </forecastday>
            <forecastday>
               <period>1</period>
               <fctext>Cloudy></fctext>
            </forecastday>
         </forecastdays>
      </txt_forecast>
   </forecast>
</response>

我目前掌握的代码是：

public String getcurrentForecast()
{
   XmlDocument doc = new XmlDocument();
   doc.Load("http://api.wunderground.com/api/74e1025b64f874f6/forecast/conditions/q/zmw:00000.1.95784.xml");
   XmlNode node = doc.DocumentElement.SelectSingleNode("/response/forecast/txt_forecast/forecastdays/forecastday");

我对XML阅读很陌生，我花了两天的时间试图理解各种来源的示例。我想使用'XMLDocument‘属性作为我的代码。

如何选择“perid0”节点并获得"fctext“文本？

Answer 1

如下所示：

    XmlDocument doc = new XmlDocument();
    doc.Load("http://api.wunderground.com/api/74e1025b64f874f6/forecast/conditions/q/zmw:00000.1.95784.xml");
    XmlNode node = doc.DocumentElement.SelectSingleNode("/response/forecast/txt_forecast/forecastdays/forecastday[period=0]/fcttext");

    String Forecast = node.InnerText;

更新:这里有一个免费的实用程序，可以帮助您快速找到正确的XPath表达式：http://www.bubasoft.net/product/xpath-builder/

Answer 2

您的XPath查询应该类似于

//forecastday/period[text()='0']/../fcttext

Answer 3

不如使用不同的库，XDocument，而不是：

byte[] data;
using (WebClient webClient = new WebClient())
    data = webClient.DownloadData(urlToDocument);

string str = Encoding.Default.GetString(data);
var doc = XDocument.Load(str);
var node = doc.Descendants("period")
                .Where(elem => elem.Value == "0")
                .First().NextNode;
var fcText = ((XElement)node).Value;