Managing SelectedItems in TreeDataGrid

Updated on Jan 14, 2026

Environment

Version	Product	Author
12.1.0	Telerik UI for .NET MAUI TreeDataGrid	Dobrinka Yordanova

Description

I want to manage the SelectedItems property in the Telerik TreeDataGrid for .NET MAUI. The SelectedItems collection is read-only, inaccessible in XAML, and cannot use two-way binding. This is by design and applies to similar collections in Telerik MAUI controls like AutoComplete Tokens, ComboBox SelectedItems, DataGrid SelectedItems, and CollectionView SelectedItems.

This knowledge base article also answers the following questions:

• How to bind the SelectedItems property in TreeDataGrid?
• How to manage the SelectedItems collection in Telerik MAUI controls?
• How to handle CollectionChanged events?

Solution

To manage the SelectedItems collection, bind it to a property in the ViewModel and handle property changes using the CollectionChanged event.

1. Define the ViewModel with an ObservableCollection for SelectedItems. Subscribe to the CollectionChanged event.

csharp

public class ViewModel : NotifyPropertyChangedBase
{
    private ObservableCollection<object> selectedItems;
    public ObservableCollection<Data> Items { get; set; }

    public ObservableCollection<object> SelectedItems
    {
        get => this.selectedItems;
        set
        {
            if (this.selectedItems != value)
            {
                if (this.selectedItems != null)
                {
                    this.selectedItems.CollectionChanged -= SelectedItems_CollectionChanged;
                }

                this.selectedItems = value;

                if (this.selectedItems != null)
                {
                    this.selectedItems.CollectionChanged += SelectedItems_CollectionChanged;
                }

                OnPropertyChanged();
            }
        }
    }

    private void SelectedItems_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        if (e.Action == NotifyCollectionChangedAction.Add)
        {
            // Handle added items
        }
        else if (e.Action == NotifyCollectionChangedAction.Remove)
        {
            // Handle removed items
        }
    }
}

2. Bind the TreeDataGrid's SelectedItems and ItemsSource properties to the ViewModel.

xaml

<telerik:RadTreeDataGrid x:Name="treeDataGrid"
                         SelectionMode="Multiple"
                         SelectedItems="{Binding SelectedItems}"
                         ItemsSource="{Binding Items}"/>

See Also

• TreeDataGrid Overview
• Selection in TreeDataGrid for .NET MAUI