title: How to disable manual input in a Telerik RadDatePicker
body: <p>I am using a Telerik <code>RadDatePicker</code>, and I want to disable input by the user, but they should be able to select from the calender.</p>
  
  <pre><code>&lt;telerik:RadDatePicker Culture="{Binding GetLanguage}" x:Name="startDate" 
                         Margin="0,5,0,5" HorizontalAlignment="Left"
                         VerticalAlignment="Center" Grid.Column="1" TabIndex="2"
                         MinWidth="120" Width="120" Height="Auto" MaxHeight="25"
                         KeyDown="filterDate_KeyDown" &gt;
  &lt;/telerik:RadDatePicker&gt;
  </code></pre>
  
  <p>I have used <code>KeyDown</code> but it did not help.</p>