WP7 Insert all linq results in an ObservableCollection - binding

Question

I parse an xml results from a webservice using linq :
XElement items = XElement.Parse(e.Result);
MyListBox.ItemsSource = from item in items.Descendants("node")
select new MyViewModel
{
...
};
This automatically populate my ListBox. But the problem is, I usually access my ObservableCollection like this :
App.MyViewModel.MyItems;
having in my xaml :
ItemsSource="{Binding MyItems,}"
How can I modify directly my ObservableCollection ? I read Cast LINQ result to ObservableCollection
and tried this :
var v = from item in items.Descendants("node")
select new MyViewModel
{
...
};
OApp.MyViewModel.MyItems = new ObservableCollection<MyViewModel>(v);
But I can't since this in WP7 (Silverlight 3), and there is no constructor like this
Thanks !

Answer 1

I'd just invent a static method like this:-
public static ObservableCollection<T> CreateObservableCollect<T>(IEnumerable<T> range)
{
var result = new ObservableCollection<T>();
foreach (T item in range)
{
result.Add(item);
}
return result;
}
Now your last line of code becomes:-
OApp.MyViewModel.MyItems = new CreateObservableCollection<MyViewModel>(v);

Answer 2

The constructor you're trying to use is in Silverlight, just not available on the phone. (as per MSDN)
Unfortunately, you'll have to populate your ObservableCollection yourself.

Answer 3

Do you need ObservableCollection? Do you need add or delete objects from collection or just update?
If only update, you can change MyViewModel.MyItems to:
public MyTypeOfCollection MyItems
{
get { return _myItems; }
set
{
_myItems = value;
OnNotifyPropertyChanged("MyItems");//invoke INotifyPropertyChanged.PropertyChanged
}
}
If you need adding or deleting of items, you can extend your collection to:
public static class Extend
{
// Extend ObservableCollection<T> Class
public static void AddRange(this System.Collections.ObjectModel.ObservableCollection o, T[] items)
{
foreach (var item in items)
{
o.Add(item);
}
}
}