C # / WPF: why the tab is not focusing properly

Question

I have a tab control

<TabControl Height="Auto" Grid.Row="1" ItemsSource="{Binding Tabs}" IsSynchronizedWithCurrentItem="True">

This is due to Tabsc ViewModel. I also used CollectionViewSourceto focus tabs

protected ObservableCollection<TabViewModel> _tabs;
protected ICollectionView _tabsViewSource;

public ObservableCollection<TabViewModel> Tabs
{
    get { return _tabs; }
}
public void OnTabsChanged(object sender, NotifyCollectionChangedEventArgs e)
{
    if (e.NewItems != null && e.NewItems.Count > 0)
        foreach (TabViewModel tab in e.NewItems)
        {
            tab.CloseRequested += OnCloseRequested;
            _tabsViewSource.MoveCurrentTo(tab); // focus newly created tab
        }
    if (e.OldItems != null && e.OldItems.Count > 0)
        foreach (TabViewModel tab in e.OldItems)
            tab.CloseRequested -= OnCloseRequested;
}

When I have more than one tab, when I create new tabs, the tabs are focused correctly

when there are no tabs, the new tabs do not seem to focus properly. pay attention to the tab title

how can i fix this? or what causes this behavior? a text box is displayed (tab contents), but the title does not appear as its selected

UPDATE

It works with a fresh file / project ... hmm ... there must be some kind of related code ... I could redo this part ...

Answer 1

IsSynchronizedWithCurrentItem="True" , TabControl.ItemsSource ICollectionView.

, ObservableCollection ICollectionView , tabboard.

public TabViewModel CurrentTabViewModel
{
    get
    {
        return _tabs.CurrentItem as TabViewModel:
    }
    set
    {
        _tabs.MoveCurrentTo(value);
    }
}

TabControl SelectedItem CurrentTabViewModel

<TabControl SelectedItem="{Binding Path=CurrentTabViewModel}" ... />

Answer 2

, , . SelectedIndex tabView = 0 → .

<TabControl Height="Auto" 
  Grid.Row="1" 
  ItemsSource="{Binding Tabs}" 
  IsSynchronizedWithCurrentItem="True" 
  SelectedIndex="0">