WPF

private void loadView(View View, _ArgsBase Args = null)
{
    ViewInfo tabInfo = new ViewInfo { View = View, EntityId = 0};

    // If the view is already open, then activate its tab
    if (TabManager.IsTabOpen(tabInfo))
    {
        TabManager.ActivateTab(tabInfo);
    }
    else
    {
        // Create an instance of the view and VM
        _DataEntryViewModelBase vm = null;
        UserControl view = null;
        string headerText = string.Empty;

        switch (View)
        {
            case View.Dashboard:
                headerText = "Dashboard";
                vm = new DashboardViewModel();
                view = new DashboardView();
                break;

            case View.JobCenter:
                headerText = "Job Center";
                vm = new JobCenterViewModel();
                view = new JobCenterView();
                break;

            case View.CompanyCenter:
                headerText = "Company Center";
                vm = new CompanyCenterViewModel();
                view = new CompanyCenterView();
                break;

            case View.MaterialsCenter:
                headerText = "Materials Center";
                vm = new MaterialsCenterViewModel();
                view = new MaterialsCenterView();
                break;
        }

        if (vm == null)
        {
            return;
        }

        // Load the vm's data and assign it to the view
        vm.Load(Args);
        view.DataContext = vm;

        // Cretae a tab and assign the view to it
        TabItem tabItem = new TabItem();

        tabItem.Header = headerText;
        tabItem.Content = view;
        tabItem.Tag = tabInfo;

        // Add the tab and activate it
        TabManager.AddTab(tabItem);
    }
}

    internal void ExpandAll(TreeViewItem tvi)
    {
        if (tvi.IsExpanded)
        {
            for (int nIndex = 0; nIndex < tvi.Items.Count; nIndex++)
            {
                TreeViewItem tviCurrent = tvi.ItemContainerGenerator.ContainerFromIndex(nIndex) as TreeViewItem;

                if ((object)tviCurrent != null)
                    ExpandAll(tviCurrent);
            }
        }
        else
        {
            if (tvi.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated)
            {
                EventHandler handler = null;

                handler = new EventHandler(delegate
                {
                    if (tvi.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
                    {
// ONLY GETS IN HERE ONCE                       tvi.ItemContainerGenerator.StatusChanged -= handler;
                        ExpandAll(tvi);
                    }
                });

                tvi.ItemContainerGenerator.StatusChanged += handler;
            }

            tvi.SetCurrentValue(TreeViewItem.IsExpandedProperty, true);
        }
    }