Question

It is MVVM project. I have a ListBox with TabControls inside of it’s items. TabItems are different for each TabControl and are binded from ViewModel:

                <TabControl ItemsSource="{Binding Tabs}"
                </TabControl >  

Tabs are:

    public ObservableCollection<TabItem> Tabs
    {   get { return tabs;  }
        set {
            tabs = value;
            value.CollectionChanged += delegate
            {
                OnPropertyChanged("Tabs");
            };

            OnPropertyChanged("Tabs"); } }

Tabs are filled by the following way only once:

                Tabs = new ObservableCollection<TabItem>();

                if (details.Image != null || !String.IsNullOrEmpty(details.Summary))
                    Tabs.Add(new TabItem() { Header = "General Info", Content = new GeneralInfo() { DataContext = ItemDetails } });  ........... 6 different types

This is a bit info about what I have. Then I dinamically change DataContext’s of this TabControls to simulate scrolling.

All info from ViewModel is binded into control, but there is a problem with TabControl. Headers are binded. but content doesnt. All headers are deselected and TabCntrol content area is empty.

I have tried to make TwoWayBinding on SelectedIndex and SelectedItem, but it doesnt help….
Seems SelectedIndex doesn’t do anything that can select TabItem.
And SelectedItem doesn’t work,becuase as I think it has new reference after each changing of data context. Because TabControl.ItemsSource re-binds and new TabItems created.

Maybe someone solved same problem and knows solution?

Thanks

Answer 1

I have solved the my issue.
The problem was that I used controls as DataContext:
– List of TabItems
– Controls inside TabItems content
There was some processes, that I dont undrstand entire. But, idea is that while DataContext’s changing, one DataContext can be assigned to 2 different TabControls. Since UI Controls cant belong to 2 parents at the same moment, so, binding that should show that controls from DataContext in content doesnt work. And doesnt throw excpetion (cause it’s binding Smile | 🙂 )

So, I remove al UI objects from DataContext, and add object models. And create UserControls that display are Views for these object models