WPF data-binding manual update

Question

I have a List<Foo> from a non-WPF assembly which I'm attempting to databind to a WPF <ListBox>. Initially, the list items display correctly, but when I add a new item to the List<Foo>, the listbox doesn't add a list item. How do I tell the list box to re-bind / update / refresh the data and show the new item?

(n.b. complete WPF n00b)

Answer 1

You should use a ObservableCollection instead, then you'll get updates automatically.

Answer 2

Although using an ObservableCollection is the best way, to answer the actual question, the way to update manually is to call BindingExpression.UpdateTarget

Answer 3

Thanks for posting this answer. Even if you use ObservableCollection, you may need to use BindingExpression.UpdateTarget. This can be the case if the collection is not in the UI thread. I've been writing some multi-threaded WPF apps, and I've been finding myself having to strip out data binding when I move model code to another thread, because I can't count on the update system to really work. While I find data binding to be a great concept, I think the opaqueness of the data binding system has been a real hindrance for my adoption of it. (Sorry for the rant!) Thanks again, Adam.