How to Bind Selected Items in WPF TreeView?

This repository describes how to bind selected items in WPF TreeView (SfTreeView).

TreeView support to select multiple items through binding the SelectedItems property from view model with ObservableCollection<object> type.

XAML

<syncfusion:SfTreeView 
            x:Name="sfTreeView"
            SelectionMode="Multiple"
            SelectedItems="{Binding SelectedNodes}"   
            ChildPropertyName="Models"
            ItemsSource="{Binding Items}" >
</syncfusion:SfTreeView>

C#

sfTreeView.SelectionMode = SelectionMode.Multiple;
sfTreeView.SetBinding(SfTreeView.SelectedItemsProperty, new Binding("SelectedNodes"));

public class ViewModel : NotificationObject
{
    public ObservableCollection<Model> Items { get; set; }

    public ObservableCollection<object> SelectedNodes { get; set; }

    public ViewModel()
    {
        Items = new ObservableCollection<Model>();
        SelectedNodes = new ObservableCollection<object>();
                 
        var country1 = new Model { State = "Australia" };
        var country2 = new Model { State = "Brazil" };
        var country3 = new Model { State = "China" };
        var country4 = new Model { State = "France" };            

        var aus_state1 = new Model { State = "New South Wales" };
        var aus_state2 = new Model { State = "Victoria" };
        var aus_state3 = new Model { State = "South Autralia" };
        var aus_state4 = new Model { State = "Western Australia" };

        var brazil_state1 = new Model { State = "Parana" };
        var brazil_state2 = new Model { State = "Ceara" };
        var brazil_state3 = new Model { State = "Acre" };

        var china_state1 = new Model { State = "Guangzhou" };
        var china_state2 = new Model { State = "Shanghai" };
        var china_state3 = new Model { State = "Beijing" };
        var china_state4 = new Model { State = "Shantou" };

        var france_state1 = new Model { State = "Pays de la Loire" };
        var france_state2 = new Model { State = "Aquitaine" };
        var france_state3 = new Model { State = "Brittany" };
        var france_state4 = new Model { State = "Lorraine" };
      
        country1.Models.Add(aus_state1);
        country1.Models.Add(aus_state2);
        country1.Models.Add(aus_state3);
        country1.Models.Add(aus_state4);

        country2.Models.Add(brazil_state1);
        country2.Models.Add(brazil_state2);
        country2.Models.Add(brazil_state3);

        country3.Models.Add(china_state1);
        country3.Models.Add(china_state2);
        country3.Models.Add(china_state3);
        country3.Models.Add(china_state4);

        country4.Models.Add(france_state1);
        country4.Models.Add(france_state2);
        country4.Models.Add(france_state3);
        country4.Models.Add(france_state4);

        Items.Add(country1);
        Items.Add(country2);
        Items.Add(country3);
        Items.Add(country4);

        SelectedNodes.Add(aus_state1);
        SelectedNodes.Add(aus_state2);
    }        
}