How to create a collection for the TabControl.ItemsSource from the class library that is created and used in the application?

Question

I have a library of custom classes with the classes MyTabItem, MyTabControl, MyGrid. When you drag MyTabItem (has a value of ViewModel) on the MyGrid, the MyGrid_Drop event is triggered. At this point, MyTabControl is created and I need to create a collection (ObservableCollection <ViewModelBase> Pages) in the application namespace and specify it in the MyTabControl.ItemsSource. After add MyTabItem to this collection.

Code in the application:

public ObservableCollection<ViewModelBase> Pages { get; set; } = new ObservableCollection<ViewModelBase>();

Code in the library:

private void MyGrid_Drop(object sender, DragEventArgs e)
        {
            if (e.Data.GetData(typeof(MyTabItem)) is MyTabItem tabItemSource)
            {
                if (InstanceTabControl.ItemsSource == null)
                {
                    // Here I need to create a collection of ViewModels with the type as the TabItemSource.Content.
                }

                if (InstanceTabControl.ItemsSource is IList list)
                {
                    var source = tabItemSource.Content;

                    list.Remove(source);
                    list.Add(source);

                    InstanceTabControl.SelectedIndex = list.Count - 1;
                }
                else
                {
                    InstanceTabControl.Items.Remove(tabItemSource);
                    InstanceTabControl.Items.Add(tabItemSource);

                    InstanceTabControl.SelectedIndex = InstanceTabControl.Items.Count - 1;
                }

            }
        }

By reference sample project PeopleDemo.

1. I can use the Func <T, TResult> delegate to create a collection in the application, but can I do without it?
2. Now the Pages collection is in ShellViewModel. It seems that I will need this collection into a collection of subcollections of view models and then for each created MyTabControl in the library to create my own subcollection. But how then to bind such a subcollection in xaml (<adc:MyTabControl ItemsSource="{Binding Pages}">)?

Please direct me how to solve this problem?

Answer 1

I solved this problem. Inside the library, I use the ObservableCollection<object> Pages collection. Each instance of MyTabControl has its own collection. I can pass a type through a generic to the class that controls the creation of collections.