title: Binding binary field to ASP.NET DataGrid Causes Error
body: <p>I have a dataset with one of it's fields named <code>"Reviewed"</code>.</p>
  
  <p>This dataset is popualted and below picture show it's data:
  <img src="https://i.stack.imgur.com/rbo1s.jpg" alt="enter image description here"></p>
  
  <p>Now Im trying to show this dataset inside a DataGrid :</p>
  
  <pre><code>&lt;ASP:TemplateColumn HeaderText="Reviewed" HeaderStyle-HorizontalAlign="center" HeaderStyle-Wrap="True"&gt;
                                      &lt;ItemStyle Wrap="false" HorizontalAlign="center" /&gt;
                                              &lt;ItemTemplate&gt;
                                                  &lt;ASP:Checkbox  Checked='&lt;%# DataBinder.Eval(Container.DataItem, "Reviewed") %&gt;' runat="server" ID="Label22" /&gt;
                                              &lt;/ItemTemplate&gt;
                                              &lt;EditItemTemplate&gt;
                                                  &lt;Asp:Checkbox id="Textbox5" width="40" Checked='&lt;%# DataBinder.Eval(Container.DataItem, "Reviewed") %&gt;' runat="server" /&gt;
                                              &lt;/EditItemTemplate&gt;
          &lt;/ASP:TemplateColumn&gt;
  </code></pre>
  
  <p>I get the following Error:</p>
  
  <blockquote>
    <p><em>Exception Details: System.InvalidCastException: Cast from type
    'DBNull' to type 'Boolean' is not valid.</em></p>
  </blockquote>
  
  <p>What I am doing wrong? Question is where DBNull comes from?</p>
  
  <p>================================ </p>
  
  <p>Update:</p>
  
  <p>Thanks for the nice answers. My main point of confusion was "STUPID" XML visualizer was wrongly showing Reviewed field as checked(as you see in the picture above). I checked the values in the dataset itself and realized all are indeed DBNUll.</p>