CODEWITHSUNDEEP
wpfdata-binding
Never
Never

Reputation: 323

ItemsSource binding and not working PropertyChanged

I set DataContext:

this.DataContext = new MainWindowViewModel();

And I am binding the ItemsSource of a TabControl, when I add a new TabItem in the contructor of MainWindowViewModel it is working! But when I add a new TabItem in an event (Click) there is no effect.

I have this property:

List<Item> _listOfItem;
public List<Item> ListOfItem
{
    get
    {
        return _listOfItem;

    }
    set
    {
        _listOfItem = value;
        PropertyChanged(this, new PropertyChangedEventArgs("ListOfItem"));
    }
}

Please help.

Upvotes: 2

Views: 4293

Answers (4)

Pongsathon.keng
Pongsathon.keng

Reputation: 1435

List will not work.

You should use ObservableCollection for the ListOfItem.

Upvotes: 1

paparazzo
paparazzo

Reputation: 45096

You need to use and ObservableCollection for the UI to see additions and deletions to the collection. It worked in the constructor as the List is was built for the the UI.

Upvotes: 1

devdigital
devdigital

Reputation: 34349

You should use an ObservableCollection, rather than a List if you wish the UI to be notified of collection changes.

ObservableCollection<Item> _listOfItem;
public ObservableCollection<Item> ListOfItem
{
    get
    {
        return _listOfItem;
    }
    set
    {
        _listOfItem = value;
        PropertyChanged(this, new PropertyChangedEventArgs("ListOfItem"));
    }
}

Note that you only need to invoke the PropertyChanged event for your ListOfItem if the reference changes after construction of your view model type. If it doesn't change, then a simple auto property will suffice for ListOfItem.

Upvotes: 2

brunnerh
brunnerh

Reputation: 184386

For collection changes you need the source collection to implement INotifyCollectionChanged, you could use an ObservableCollection<T> (which implements it) instead of a List<T>.

Upvotes: 1

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