Question

I want to pull data from a database to display into a ComboBox, and then allow users to select values from that ComboBox and add them into a ListBox (via add/remove buttons). Would I be able to get away with using an ObservableCollections to hold the database values to bind to the ComboBox, since it implements INotifyPropertyChanged (and CollectionChanged)? Sorry if this is a basic question, I starting learning WPF about a month ago.

I’ve read over the article (very well done) by Sacha Barber.

And I’ve looked over the MSDN page on ObservableCollection.

What would be the advantages/disadvantages of using an ObservableCollection vs a List (which I know does not implement INotifyPropertyChanged)?

Answer 1

If the items in your combobox don’t change (i.e. you don’t add/remove/update items), then List will probably be OK for your needs (ObservableCollection will be too) if you manually notify that your List property changed when you affect it.

public List<X> MyList
{
    get
    {
        ...
    }

    set
    {
        if (... != value)
        {
            ... = value;
            if (this.PropertyChanged != null)
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs("MyList"));
            }
        }
    }
}

....

this.MyList = new List<X> { new X(...), new X(...) };

If you plan to add/remove or update items in your combobox (without creating a new MyList object, i.e. using this.MyList.Add(...)), then use ObservableCollection that is able to notify when the collection is updated (so it can update bindings).