Get XML attribute with C#

问题

I have an XML file like the following.

<div class="time">
   <span class="title">Bla: </span>
   <span class="value">Thu 20 Jan 11</span>
</div>

How can I get value "Thu 20 Jan 11" with C#? thanks in advance

回答1:

Sounds like you rather need an HTML Parser IMHO. if so, then Take a look at Html Agility Pack

回答2:

Given that you do have an XML file like you say, then you need could load the file into an XmlDocument and find what you want using XPath:

class Program
    {
        static void Main(string[] args)
        {
            var xml = "<div class=\"time\">" +
                        "<span class=\"title\">Bla: </span>" +
                        "<span class=\"value\">Thu 20 Jan 11</span>" +
                        "</div>";
            var document = new XmlDocument();

            try
            {
                document.LoadXml(xml);
            }
            catch (XmlException xe)
            {
                // Handle and/or re-throw
                throw;
            }

            var date = document.SelectSingleNode("//span[@class = 'value']").InnerText;

            Console.WriteLine(date);

            Console.ReadKey();
        }
    }

Output: Thu 20 Jan 11

回答3:

I wrote a little snippet, which does it for you...

public void Test(String source)
{

XElement elem = XElement.Parse(source);

var query = (from x in elem.Descendants("span") select x.Value).LastOrDefault();

Console.WriteLine(query.ToString());
}

回答4:

Using XPath queries may be an elegant solution too. See this knowledge base article for a brief how-to: http://support.microsoft.com/kb/308333

This of course requires the document to be strictly correct XML, which XHTML is. Unfortunately HTML input often contains syntax errors...

Cheers, Matthias

回答5:

As said you could parse it as HTML.

However treating it as a XML document you can read the value from the node by using the XPath: /div/span[@class="value"]

You can also use XDocument to select a node value from a known XPath or by searching through descendant nodes. Using LINQ this becomes very easy to match on attribute value. Link here

回答6:

This is as sgrassie's answer but using linq to xml, I like more this code, but is up to you.

string xml = "<div class=\"time\"><span class=\"title\">Bla: </span><span class=\"value\">Thu 20 Jan 11</span></div>";
StringReader sr = new StringReader(xml);
XDocument xdoc = XDocument.Load(sr);
var date = xdoc.Element("div").Elements("span").Where(m => ((string)m.Attribute("class")) == "value").FirstOrDefault();
Console.WriteLine(date.Value);
Console.ReadLine();

回答7:

Below is the code in VTD-XML:

  VTDGen vg = new VTDGen();
  System.Text.Encoding eg = System.Text.Encoding.GetEncoding("UTF-8");
    String XML = "<div class=\"time\">" +                         
                 "<span class=\"title\">Bla: </span>" +                     
                 "<span class=\"value\">Thu 20 Jan 11</span>" +                     
                 "</div>";
    vg.setDoc(eg.GetBytes(XML));
    vg.parse(true);
    VTDNav vn = vg.getNav();
    AutoPilot ap = new AutoPilot(vn);
    ap.selectXPath("/div/span[@class='value']/text()");
    int i = ap.evalXPath();
    if (i!=-1)
        Console.WriteLine(vn.toString(i));

回答8:

Ok, guyes I am putting the fragment of the code. The problem is that when I use XPath: //@* I get all the list correctly. Also I tried //@class and it returned the all the class values - OK. But when I put //span[@class='value'] i got blank list. Also I've tried several variations and it seems that when I put attribute equal to something //title[@type='html'] I am getting blank list.

<feed xmlns="w3.org/2005/Atom">
  <updated>2011-01-20T08:33:23Z</updated>
  <title type="html">grgrgr</title>
  <entry>
    <title type="html">Blog post : Estiatoria</title>
    <content type="xhtml">
      <div xmlns="w3.org/1999/xhtml">
        <div class="due">
          <span class="title">Due:</span>
          <span class="value">20 Jan 11</span>
        </div>
      </div>
    </content>
  </entry>
</feed>

来源：https://stackoverflow.com/questions/4747269/get-xml-attribute-with-c-sharp

标签

xml

linq-to-xml