title: Use two datepicker controls to specify a start and end date?
body: <p>I am trying to use two DatePicker controls to specify a start and end date within a specified range, whilst also limiting the selections so that the start date is before the end date and the end date is after the start date.</p>
  
  <p>So I have tried this XAML:</p>
  
  <pre><code>&lt;GroupBox Grid.Row="1" Header="Run Length"&gt;
              &lt;StackPanel Orientation="Horizontal"&gt;
                  &lt;DockPanel VerticalAlignment="Top"&gt;
                      &lt;Label DockPanel.Dock="Left"&gt;Start Date&lt;/Label&gt;
                      &lt;DatePicker DockPanel.Dock="Right" Height="25" SelectedDate="{Binding Path=RunStartDate, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" DisplayDateStart="{Binding Path=MinDate, Mode=OneWay, NotifyOnSourceUpdated=True}" DisplayDateEnd="{Binding Path=RunEndDate, Mode=OneWay, NotifyOnSourceUpdated=True}"&gt;&lt;/DatePicker&gt;
                  &lt;/DockPanel&gt;
                  &lt;DockPanel VerticalAlignment="Top"&gt;
                      &lt;Label DockPanel.Dock="Left"&gt;End Date&lt;/Label&gt;
                      &lt;DatePicker DockPanel.Dock="Right" Height="25" SelectedDate="{Binding Path=RunEndDate, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" DisplayDateStart="{Binding Path=RunStartDate, Mode=OneWay, NotifyOnSourceUpdated=True}" DisplayDateEnd="{Binding Path=MaxDate, Mode=OneWay, NotifyOnSourceUpdated=True}"&gt;&lt;/DatePicker&gt;
                  &lt;/DockPanel&gt;
              &lt;/StackPanel&gt;
          &lt;/GroupBox&gt;
  </code></pre>
  
  <p>However when the values of 'MinDate' and 'MaxDate' change, the DatePickers do not? Can anyone explain why?</p>
  
  <p>Thanks,
  Alex.</p>