Tip #9 will examine something that seems like it should work according to the documentation on MSDN, but I have seen it not work as expected.
When using ObservableCollection<T>, if some code in your application needs to react when items are added or removed from the collection the CollectionChanged event can be handled.
private ObservableCollection<Pill> _pills = new ObservableCollection<Pill>();
public MainWindow()
{
InitializeComponent();
Pills.CollectionChanged += Pills_CollectionChanged;
}public ObservableCollection<Pill> Pills
{
get { return _pills; }
set { _pills = value; }
}void Pills_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
// Pills Collection Changed - do something
}
The issue I have encountered with this code is that setting that value of the Pills property directly does not always fire the CollectionChanged event.
Pills = someOtherPillCollection;
What I did to work around this was to remove the property setter and only work with the collection through its properties. In this case, by using Clear() and Concat<T>().
Pills.Clear();
Pills.Concat<Pill>(someOtherPillCollection);
ObservableCollection does not have an AddRange() method. You could write your own extension method to do it, but I prefer to use the LINQ extension method Concat<T>().
Has anyone else seen this same issue?
