Notifying WPF DataGrid on changes

Question

I have a DataGrid bound to the ICollectionView (with filter on). More specifically, I have set view.Filter = SomeFilteringFunction which uses public DateTime DateFrom { get... set... } property, also bound to the DatePicker .

Well, and now, when I change DatePicker , bound property DateFrom is correctly changed but the DataGrid is not obviously re-filtered.

What is the most right way how to notify DataGrid to update itself?

Thank you in advance!

James

Answer 1

You shouldn't be binding directly to the ICollectionView, rather you bind to the source collection, and then apply the filter to the ICollectionView returned by CollectionViewSource.GetDefaultView.

<DataGrid ItemsSource="{Binding MyCollection}" />

// should raise INotityPropertyChange.PropertyChanged
public ObservableCollection<Entity> MyCollection { get; set; }

MyCollection = new ObservableCollection<Entity>(ctx.EntitySet)); 
ICollectionView view = CollectionViewSource.GetDefaultView(MyCollection);
view.Filter = SomeFilteringFunction;

Then when the value of the DatePicker changes you need to tell the ICollectionView to update.

ICollectionView view = CollectionViewSource.GetDefaultView(MyCollection);
view.Refresh();

Answer 2

You can subscribe to the PropertyChanged event (which i assume you implemented on the class) and refresh the view in the handler:

var view = CollectionViewSource.GetDefaultView(Collection);
if (view != null)
{
    view.Refresh();
}

Not sure if there is a cleaner way, though, but i'm quite positive you need to make that Refresh call at one point.