title: Automatic validation in a DataGridView
body: <p>I'm not new to WinForms but I have always "rolled my own" when it comes to validation - and I think it's time to take advantage of the built-in stuff. I Googled around for some basics but I'm not finding what I need...</p>
  
  <p>I've got a DataGridView. I have a (custom) object that has four String properties. I am getting a List&lt;> of them from an XML file.</p>
  
  <p>So when I do this:</p>
  
  <pre><code>dgv.DataSource = genericListOfStationObjects;
  </code></pre>
  
  <p>the rows <em>do</em> show up correctly in the DataGridView. So the databinding is working just fine - at least in the "incoming" direction.<br><br>That's good.<br>But what I need to do is:</p>
  
  <ol>
  <li>track IsDirty on each row (without manually adding a flag?)</li>
  <li>visually indicate (within the DataGridView) if any of the values in the DataGridView's cells are invalid. (I have validation methods on my custom object (of which the List&lt;> is comprised.) I cannot get those "error glyphs" to show up. I've tried all the SO posts I could find on that...</li>
  </ol>
  
  <p>Thank you very much,<br>Eliezer</p>