Multiple selection

[Vicente]

Hi,

I have a ViewModel with a collection binded to my user control, and then one of the ViewModel properties is binded to a RadTreeView. I need to support multiple selection, but it seems I can't bind SelectedItems property. Any tips on how to achieve this?

Regards

[Pavel R. Pavlov]

Hello Vicente,

In order to achieve this you can bind  a boolean property of your ViewModels (ex. Selected) to the IsSelected property of the RadTreeViewItem via StyleBindings. For more information you can read this article.

Feel free to ask if you have any questions.

All the best,
Pavel R. Pavlov
the Telerik team

[Vicente]

Hi Pavel,

ok, I see how it works. But ideally what I would like to have is something like this. A ViewModel that has two properties:

- Items: the collection bound to the ItemsSource property of the tree.
- SelectedItems: the collection of selected items boud to the SelectedItems property of the tree (this is what I can't do as SelectedItems in RadTreeView does not have a public set).

If I went and added a IsSelected property to all my items, I would need somehow to have my items tell the ViewModel that contains the SelectedItems collection about changes on the IsSelected property so it is updated correctly. Is there not an easier way to handle this?

Regards,

Vicente

[Pavel R. Pavlov]

Hello Vicente,

You can achieve your goal by using System.Windows.Interactivity.Behavior<T>. Please take a look at the attached project and let us know if it works for you.

Regards,
Pavel R. Pavlov
the Telerik team

[Vicente]

Hi Pavel,

this has worked wonderfully, thanks a lot for providing the sample. Regards!

Vicente

[Sahi]

Hi Pavel,

I wrote below show all the items selected but only last item is selected . I need to show multiple items selected at one time.

Before that i experimented like this below set of code . but it didn't work. Please help!

   <telerik:RadTreeView.ItemContainerStyle>

<Setter Property="IsSelected" Value="True" >

</telerik:RadTreeView.ItemContainerStyle>

 

 

[Pavel R. Pavlov]

Hi Sahi,

I would like to turn your attention to the definition of the ItemContainerStyle. You should set that property to a Style targeting the RadTreeViewItem control. For example you can use this code:

<telerik:RadTreeView >
    <telerik:RadTreeView.ItemContainerStyle>
        <Style TargetType="telerik:RadTreeViewItem">
            <Setter Property="IsSelected"  Value="True" />
        </Style>
    </telerik:RadTreeView.ItemContainerStyle>
</telerik:RadTreeView>

Also, you need to configure the RadTreeView control to select more than one of its items. This can be done by using the SelectionMode property. By default this property is set to Single which forces the RadTreeView control to select only one of its items. In your case can try setting it to Multiple.

When this configuration is applied the earlier provided snippet it looks like this:

<telerik:RadTreeView SelectionMode="Multiple">
    <telerik:RadTreeView.ItemContainerStyle>
        <Style TargetType="telerik:RadTreeViewItem">
            <Setter Property="IsSelected"  Value="True" />
        </Style>
    </telerik:RadTreeView.ItemContainerStyle>
</telerik:RadTreeView>

I hope this information is helpful.

Regards,
Pavel R. Pavlov
Telerik