title: Check/uncheck CheckBox (GridViewCheckBoxColumn)
body: <p>I can't check/uncheck the <code>CheckBox</code> in the <code>gridview</code> cell. I think it is disabled. How am I going to do this? Looking for your responce..</p>
  
  <p><img src="https://i.stack.imgur.com/nVkXB.png" alt="Checkbox"></p>
  
  <p>Xaml Code:</p>
  
  <pre><code>&lt;telerik:RadGridView.Columns&gt;
                      &lt;telerik:GridViewDataColumn Header="Customer"/&gt;
                      &lt;telerik:GridViewCheckBoxColumn Header="Assigned" AutoSelectOnEdit="True"/&gt;
                  &lt;/telerik:RadGridView.Columns&gt;
              &lt;/telerik:RadGridView&gt;
  &lt;/telerik:RadGridview.Columns&gt;
  </code></pre>