title: DataGridColumn Readonly via converter
body: <p>I have a Datagrid with three columns.</p>
  
  <p><strong>I want the second column readonly if the value of first column is not null</strong></p>
  
  <p>I tried with a converter but there's something wrong.
  Any ideas why? </p>
  
  <pre><code>&lt;UserControl.Resources
      &lt;Converters:StringToBoolConverter x:Key="stringToBoolConverter"/&gt;
  &lt;/UserControl.Resources&gt;
  
     .......................................
  
  &lt;DataGrid Grid.Column="2" Grid.RowSpan="2" HorizontalAlignment="Stretch" Name="_edgFAI" AddCommandVisibility="Visible" InternalCommandsHandling="False" DeleteCommandVisibility="Visible" SaveCommandVisibility="Visible"&gt;
      &lt;DataGrid.Columns&gt;
           &lt;DataGridTextColumn Header="IdenFAI" Tag="ID_FAI" Width="Auto" IsReadOnly="True"/&gt;
           &lt;DataGridTextColumn Header="Description" Tag="DS_FAI" Width="Auto" IsReadOnly="{Binding Path=ID_FAI, Converter={StaticResource stringToBoolConverter}}" /&gt;
           &lt;DataGridTextColumn Header="DocumentState" Tag="FAI_STATE" Width="SizeToHeader" IsReadOnly="True"/&gt;
      &lt;/DataGrid.Columns&gt;
  &lt;/DataGrid&gt;
  </code></pre>