ObservableCollection not updating View

Question

I am just starting with MVVM and have hit a hurdle that I hope someone can help me with. I am trying to create a simple View with 2 listboxes. A selection from the first lis

Answer 1

You need to raise the change notification on the Level2MenuItems property.

Instead of having

public ObservableCollection Level2MenuItems { get; set; }

you need

private ObservableCollection _level2MenuItems;
public ObservableCollection Level2MenuItems
{
    get { return _level2MenuItems; }
    set 
     {
        _level2MenuItems = value; 
        RaisePropertyChanged("Level2MenuItems");
     }
 }

The reason the former works in the constructor is that the Binding has not taken place yet. However since you are changing the reference via a command execute which happens after the binding you need to tell view that it changed