Changing the DataContext of a Pane is not working

[Patrick]

Hello,
create a new SIlverlight 5 application, add references to Telerik.Windows.Controls, Telerik.Windows.Controls.Docking and Telerik.Windows.Controls.Navigation.

Then replace MainPahe.xaml with:

<UserControl
  x:Class="SilverlightApplication1.MainPage"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:tk="http://schemas.telerik.com/2008/xaml/presentation"
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="d"
  d:DesignHeight="300" d:DesignWidth="400">

  <tk:RadDocking>
    <tk:RadSplitContainer>
      <tk:RadPaneGroup>
        <tk:RadPane Name="Pane"
                    Header="Pane">
          <StackPanel Margin="5">

            <TextBlock HorizontalAlignment="Left"
                       Margin="2"
                       Text="{Binding}" />

            <tk:RadButton Content="Context to 123"
                          HorizontalAlignment="Left"
                          Margin="2"
                          Click="RadButton_Click" />

            <tk:RadButton Content="Context to ABC"
                          HorizontalAlignment="Left"
                          Margin="2"
                          Click="RadButton_Click_1" />

          </StackPanel>
        </tk:RadPane>
      </tk:RadPaneGroup>
    </tk:RadSplitContainer>
  </tk:RadDocking>
</UserControl>

and replace MainPage.xaml.cs with:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace SilverlightApplication1
{
  public partial class MainPage : UserControl
  {
    public MainPage()
    {
      InitializeComponent();
      Pane.DataContext = "None";
    }

    private void RadButton_Click(object sender, RoutedEventArgs e)
    {
      Pane.DataContext = "123";
    }

    private void RadButton_Click_1(object sender, RoutedEventArgs e)
    {
      Pane.DataContext = "ABC";
    }
  }
}

Now run the application.
The DataContext that is set at the beginning is working, but the change of the DataContext is not propagated to the children controls.
If I set the DataContext of the main page or of the StackPanel, it works correctly!

Patrick

[Rosen Vladimirov]

Hi Patrick,

When you change the DataContext, it is not used on the children of the RadPane by design. In order to get it working, you will have to change the DataContext of RadPane's Content (as you have noticed, if you set the DataContext of the StackPanel, it works fine). Changing the DataContext of RadPane is only applied on the Header area of the Pane.

Hopefully this helps. Feel free to contact us in case you have any problems or concerns. 

Regards,
Rosen Vladimirov
Telerik

[Patrick]

Rosen,
that's not totally true: when I set the DataContext on the RadPane the first time, it is working. So this is confusing: why does it work the first time and not the second one?
Also, if this is by design, this should be documented. Because the Silverlight way of doing things is that children elements inherit the DataContext of their parent.
Patrick

[Rosen Vladimirov]

Hi Patrick,

When you set the DataContext immediately after InitializeComponent() or in XAML, the Content of RadPane is still inside it, as this is the way it is defined in XAML. But internally we are applying some changes, so if you use a timer and set the DataContext on RadPane after the internal operation has finished, the TextBlock will not receive this DataContext. That's why we recommend you to set the DataContext on the Content itself.

Hopefully this helps. Feel free to contact us in case you have any problems or concerns. 

Regards,
Rosen Vladimirov
Telerik