title: C# HtmlAgilityPack Working On HtmlNodeCollection
body: <p>Here is html codes :   </p>
  
  <pre><code>&lt;div id="frmPnlProductGallery"&gt;
          &lt;ul class="clearfix"&gt;
                  &lt;li&gt;
                      &lt;a data-index="0" class="productItem" href="javascript:void(0)" title="https://file.digi-kala.com/digikala/Image/Webstore/ProductPhoto/P_118274/Original/234942.jpg" rel="dk-gallery-item" data-imgurl="https://file.digi-kala.com/digikala/Image/Webstore/ProductPhoto/P_118274/Original/234942.jpg"&gt;
                      &lt;/a&gt;
                  &lt;/li&gt;
                  &lt;li&gt;
                      &lt;a data-index="1" class="productItem" href="javascript:void(0)" title="https://file.digi-kala.com/digikala/Image/Webstore/ProductPhoto/P_118274/Original/c9ebc3.jpg" rel="dk-gallery-item" data-imgurl="https://file.digi-kala.com/digikala/Image/Webstore/ProductPhoto/P_118274/Original/c9ebc3.jpg"&gt;
                      &lt;/a&gt;
                  &lt;/li&gt;
                  &lt;li&gt;
                      &lt;a data-index="2" class="productItem" href="javascript:void(0)" title="https://file.digi-kala.com/digikala/Image/Webstore/ProductPhoto/P_118274/Original/12199f.jpg" rel="dk-gallery-item" data-imgurl="https://file.digi-kala.com/digikala/Image/Webstore/ProductPhoto/P_118274/Original/12199f.jpg"&gt;
                      &lt;/a&gt;
                  &lt;/li&gt;
          &lt;/ul&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>Now i want to grab three <code>title=</code> into a <code>List&lt;string&gt;</code>.<br>
  Here is the codes :   </p>
  
  <pre><code>var lis = htmlDoc.DocumentNode.SelectNodes("//div[@id='frmPnlProductGallery']//ul//li");
  List&lt;string&gt; ls_images = new List&lt;string&gt;();
  </code></pre>
  
  <p>Now how can i grab those three titles?   </p>