<CategoryAttribute("Common Properties")>
Public Property ExpandedItem As Object

Dim instance As UXTreeView
Dim value As Object
 
instance.ExpandedItem = value
 
value = instance.ExpandedItem

[CategoryAttribute("Common Properties")]
public object ExpandedItem {get; set;}

public read-write property ExpandedItem: TObject; 

CategoryAttribute("Common Properties")
public function get,set ExpandedItem : Object

[CategoryAttribute("Common Properties")]
public: __property Object* get_ExpandedItem();
public: __property void set_ExpandedItem( 
   Object* value
);

[CategoryAttribute("Common Properties")]
public:
property Object^ ExpandedItem {
   Object^ get();
   void set (    Object^ value);
}

public class CompanyEmployee : ModelBase
{
    private String _name;

    public String Name
    {
        get { return this._name; }
        set
        {
            if (this._name != value)
            {
                this._name = value;
                OnPropertyChanged("Name");
            }
        }
    }
}

public class Company : ModelBase
{
    private string _section;
    private ObservableCollection<CompanyEmployee> _employees;

    public string Section
    {
        get { return this._section; }
        set
        {
            if (this._section != value)
            {
                this._section = value;
                OnPropertyChanged("Section");
            }
        }
    }

    public ObservableCollection<CompanyEmployee> Employees
    {
        get { return this._employees; }
        set
        {
            if (this._employees != value)
            {
                this._employees = value;
                OnPropertyChanged("Employees");
            }
        }
    }

    public Company()
    {
        this.Employees = new ObservableCollection<CompanyEmployee>();
    }
}

public class CompanyViewModel : ViewModelBase
{
    private ObservableCollection<Company> _companies;
    private object _expandedItem;
    private object _processedItem;

    public ObservableCollection<Company> Companies
    {
        get { return this._companies; }
        set
        {
            if (this._companies != value)
            {
                this._companies = value;
                OnPropertyChanged("Companies");
            }
        }
    }

    public object ExpandedItem
    {
        get { return this._expandedItem; }
        set
        {
            if (this._expandedItem != value)
            {
                this._expandedItem = value;
                Company obj = value as Company;
                ObservableCollection<CompanyEmployee> data = new ObservableCollection<CompanyEmployee>();

                //using thread
                if (obj != null && obj.Employees.Count == 0)
                {
                    var t = new Thread(() =>
                    {
                        try
                        {
                            Thread.Sleep(300);
                            for (int i = 0; i < 20; i++)
                            {
                                data.Add(new CompanyEmployee()
                                {
                                    Name = obj.Section + ", Employee " + i.ToString()
                                });
                            }
                            System.Windows.Deployment.Current.Dispatcher.BeginInvoke(() =>
                            {
                                obj.Employees = data;
                                this.ProcessedItem = value;
                            });
                        }
                        catch
                        {
                            System.Diagnostics.Debug.WriteLine("Debug");
                        }
                    });
                    t.Start();                        
                }
                else
                    this.ProcessedItem = value;
                OnPropertyChanged("ExpandedItem");
            }
        }
    }

    public object ProcessedItem
    {
        get { return this._processedItem; }
        set
        {
            if (this._processedItem != value)
            {
                this._processedItem = value;
                OnPropertyChanged("ProcessedItem");
            }
        }
    }

    public CompanyViewModel()
    {
        this.LoadData();
    }

    private void LoadData()
    {
        this.Companies = new ObservableCollection<Company>();
        this.Companies.Add(new Company() { Section = "Human Resource" });
        this.Companies.Add(new Company() { Section = "Development and Training" });
        this.Companies.Add(new Company() { Section = "Developer" });
        this.Companies.Add(new Company() { Section = "Support" });
        this.Companies.Add(new Company() { Section = "Project Manager" });
    }
}

<Intersoft:UXPage>
    <Intersoft:UXPage.Resources>
        <ViewModel:CompanyViewModel x:Key="CompanyViewModel" />
    </Intersoft:UXPage.Resources>
    <Grid x:Name="LayoutRoot">
        <Grid.Resources>
            <Intersoft:HierarchicalDataTemplate x:Key="CompanyEmployeeTemplate" ItemsSource="{Binding Employees}">
                <TextBlock Text="{Binding Name}" />
            </Intersoft:HierarchicalDataTemplate>            
            <Intersoft:HierarchicalDataTemplate x:Key="CompanyTemplate" ItemTemplate="{StaticResource CompanyEmployeeTemplate}" ItemsSource="{Binding Employees}">
                <TextBlock Text="{Binding Section}" />
            </Intersoft:HierarchicalDataTemplate>
        </Grid.Resources>
        <Intersoft:UXTreeView TreeExpandMode="Multiple" Height="300" 
                IsLoadOnDemand="True" BusyLatency="0.002" LoadOnDemandMode="UseProcessedItem"
                ExpandedItem="{Binding ExpandedItem, Mode=TwoWay}" 
                ProcessedItem="{Binding ProcessedItem, Mode=TwoWay}" 
                ItemsSource="{Binding Companies}" EnableSlidingAnimation"False"
                DataContext="{StaticResource CompanyViewModel}" 
                ItemTemplate="{StaticResource CompanyTemplate}">
        </Intersoft:UXTreeView>
    </Grid>
</Intersoft:UXPage>