title: How to use SetElementValue on XDocument
body: <p>This is the sample of my xml</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;SearchHistory&gt;
      &lt;Search&gt;
          &lt;title&gt;Text 1&lt;/title&gt;
          &lt;count&gt;0&lt;/count&gt;
      &lt;/Search&gt;
      &lt;Search&gt;
          &lt;title&gt;Text 2&lt;/title&gt;
          &lt;count&gt;0&lt;/count&gt;
      &lt;/Search&gt;
  &lt;/SearchHistory&gt;
  </code></pre>
  
  <p>And I want to change the value of <strong>count</strong> of Text 1</p>
  
  <p>this is what i tried:</p>
  
  <pre><code>xdoc.Descendants("Search")
      .Where(x =&gt; x.Element("title").Value == tbSearch.Text)
      .Single().SetElementValue("count", curCount);
  </code></pre>