title: C# loop through xml to get innertext value of a specific subnode
body: <p>I have XML document look like this:</p>
  
  <pre><code>&lt;Runs&gt;
   &lt;Run&gt;
    &lt;LotInfo&gt;
     &lt;Column name="Entity"&gt;HST123,&lt;/Column&gt; 
     &lt;Column name="Product"&gt;XXX123&lt;/Column&gt; 
     &lt;Column name="WSOp"&gt;1234&lt;/Column&gt; 
     &lt;Column name="Route"&gt;V234&lt;/Column&gt; 
     &lt;Column name="Recipe" /&gt; 
     &lt;Column name="LotNumber"&gt;K898722&lt;/Column&gt; 
     &lt;Column name="RunStartTime"&gt;2014-05-20T17:43:11.8872105&lt;/Column&gt; 
    &lt;/LotInfo&gt;
    &lt;Operations&gt;
     &lt;Operation type="INTRODUCTION"&gt;
     &lt;Column name="Size"&gt;1490&lt;/Column&gt; 
     &lt;Column name="TimeStamp"&gt;2014-05-20T17:43:11.8872105&lt;/Column&gt; 
     &lt;Column name="Operator"&gt;nismail9&lt;/Column&gt; 
     &lt;Column name="Description"&gt;
      &lt;![CDATA[ Unknown ]]&gt; 
     &lt;/Column&gt;
    &lt;Column name="Status"&gt;Success&lt;/Column&gt; 
    &lt;/Operation&gt;
    &lt;Operation type="RNUCHECK"&gt;
     &lt;Column name="Size"&gt;1490&lt;/Column&gt; 
     &lt;Column name="TimeStamp"&gt;2014-05-20T17:43:15.3091731&lt;/Column&gt; 
     &lt;Column name="Operator"&gt;nismail9&lt;/Column&gt; 
     &lt;Column name="Description"&gt;
      &lt;![CDATA[ ]]&gt; 
     &lt;/Column&gt;
     &lt;Column name="Status"&gt;True&lt;/Column&gt; 
    &lt;/Operation&gt;
    &lt;Operations&gt;
     &lt;Operation type="INTRODUCTION"&gt;
     &lt;Column name="Size"&gt;1490&lt;/Column&gt; 
     &lt;Column name="TimeStamp"&gt;2014-05-20T17:58:47.0830259&lt;/Column&gt; 
     &lt;Column name="Operator"&gt;nismail9&lt;/Column&gt; 
     &lt;Column name="Description"&gt;
      &lt;![CDATA[ Unknown ]]&gt; 
     &lt;/Column&gt;
     &lt;Column name="Status"&gt;Success&lt;/Column&gt; 
     &lt;/Operation&gt;
    &lt;/Operations&gt;
   &lt;/Run&gt;
  &lt;/Runs&gt;
  </code></pre>
  
  <p>I want to loop through the whole XML to get the inner text value. I need to get the time stamp for the node <code>&lt;Operation type="INTRODUCTION"&gt;</code>. Whenever i get the <code>&lt;Operation type="INTRODUCTION"&gt;</code>, I will go to get the time stamp under this node: <code>&lt;Column name="TimeStamp"&gt;2014-05-20T17:43:11.8872105&lt;/Column&gt;</code> which is <code>2014-05-20T17:43:11.8872105</code>.</p>
  
  <p>I have a code to get the value, but I don't know how to loop through the whole text to get all of them. I am only able to get one.</p>
  
  <p>My code so far:</p>
  
  <pre><code>XmlDocument readDoc = new XmlDocument();
              readDoc.Load(fileName);
              int count = readDoc.SelectNodes("/Runs/Run/Operations/Operation[@type='INTRODUCTION']").Count;
              MessageBox.Show(count.ToString());
  
                          var node = readDoc.SelectSingleNode("/Runs/Run/Operations/Operation[@type='INTRODUCTION']/Column[@name='TimeStamp']");
  MessageBox.Show(node.InnerText);
  </code></pre>