title: Get row in datagrid
body: <p>I tried to get row like this :</p>
  
  <pre><code>DataGridRow row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(i);
  TextBlock cellContent = dataGrid.Columns[0].GetCellContent(row) as TextBlock;
  </code></pre>
  
  <p>But I only got <code>null</code>. Is there another solution? What am I doing wrong?</p>
  
  <p>I want to get data from my cells. My cells are checkboxes.</p>