Question

I have a list view that has a column databound to a list.Count see below:

<ListView.View>
    <GridView>
        <GridViewColumn Header="Contacts" DisplayMemberBinding="{Binding Path=Contacts.Count}"/>
        <GridViewColumn Header="Notes" DisplayMemberBinding="{Binding Path=Notes.Count}"/>
    </GridView>
</ListView.View>

The List implements INotifyCollectionChanged. But when I add an item to the list the listview column does not get refreshed. am I doing something wrong in my binding? I can do the following:

    void _Contacts_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        OnPropertyChanged("Contacts");
    }

Which basically raises the PropertyChanged event of the collection. This forces wpf to rebind, but I would rather not have an abundance of events flying through my code(especially the unnecessary ones).

Any ideas?

Answer 1

The problem is that while you raise a property changed for Contacts, you do not raise an event for the Count property..

You can solve this with

OnPropertyChanged("Count")

in your list, since your list implements the INotifyPropertyChanged interface…