Article information
Article relates to	Synchronizing TreeView and TextBox
Created by	Ivan Efimov
Last modified	11-06-2009
Last modified by	Nikolay Atanasov

Some times you need a synchronous work between a TreeView and a TextBox. Of course they both are bound to a custom business object.

Even this case looks pretty simple it is not so easy in Silverlight. The reason is that you cannot rely on the Focus mechanism in Silverlight. The change notifications of GotFocus and LostFocus occur asynchronously. Therefore,  you should use the Dispatcher and you implement an attached behavior for the edit control (the TextBox). Below is a brief explanation of the implementation.

Constructing the base:

1. Construct your Business object (preview the myData.cs file).
2. Implement both key controls in your xaml: a RadTreeView as the treeview and the TextBox as the editor (preview the MainPage files - Xaml and C#).
3. Implement an items source for the treeview (MainPage.xaml file).
4. Bind both the treeview and the editor (MainPage.xaml file).

Synchronizing the editor's content to follow the treeview selection:

5. Handle the SelectionChanged event of the RadTreeView (MainPage.* files).
6. Initialize the editor's DataContext with the current tree selection (MainPage.cs file).

Synchronizing the tree selection with the editor's content:

7. Implement an attached behavior for the editor (TextBoxExtensions.cs file). Please note that in the attached project we are using the UpdateSourceOnTextChanged attached property to spread the editor's content. Actually we are using the TextBox's TextChanged event.

For the sake of the demonstration we implemented two example pairs (tree and editor). One with entire logic explained above and another without the attached behavior.

Attached you can find the example project.