Checkbox Column - cascade select about avalonia.controls.treedatagrid HOT 7 OPEN

<TreeDataGrid.Resources>
                        <DataTemplate x:Key="FileNameCell1" DataType="m:FileTreeNodeModel">
                            <CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}" />
                        </DataTemplate>

Columns =
                {
                    new TemplateColumn<FileTreeNodeModel>(
                            "Name",
                            "FileNameCell1",
                            options: new ColumnOptions<FileTreeNodeModel>
                            {
                                CanUserResizeColumn = false
                            }),

    public class TreeItem : INotifyPropertyChanged
    {
        private bool _checked;

        public TreeItem()
        {
            Children.CollectionChanged += DataCollectionChanged;
        }

        public string Display { get; set; }

        public dynamic Object { get; set; }

        public bool Checked
        {
            get
            {
                return _checked;
            }
            set
            {
                _checked = value;

                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs(nameof(Checked)));
                }
            }
        }

        public ObservableCollection<TreeItem> Children { get; set; } = new ObservableCollection<TreeItem>();

        public event PropertyChangedEventHandler? PropertyChanged;

        public override string ToString()
        {
            return Display;
        }

        private void DataCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.OldItems != null)
            {
                foreach (INotifyPropertyChanged item in e.OldItems)
                {
                    item.PropertyChanged -= ItemPropertyChanged;
                }
            }

            if (e.NewItems != null)
            {
                foreach (INotifyPropertyChanged item in e.NewItems)
                {
                    item.PropertyChanged += ItemPropertyChanged;
                }
            }
        }

        public static void ItemPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (sender is TreeItem item)
            {
                var isChecked = item.Checked;

                foreach(var child in item.Children)
                {
                    child.Checked = isChecked;

                    ItemPropertyChanged(child, null);
                }
            }
        }
    }