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copied!<p>You can use the following class :</p> <pre><code>public class BoundObservableCollection<T, TSource> : ObservableCollection<T> { private ObservableCollection<TSource> _source; private Func<TSource, T> _converter; private Func<T, TSource, bool> _isSameSource; public BoundObservableCollection( ObservableCollection<TSource> source, Func<TSource, T> converter, Func<T, TSource, bool> isSameSource) : base() { _source = source; _converter = converter; _isSameSource = isSameSource; // Copy items AddItems(_source); // Subscribe to the source's CollectionChanged event _source.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(_source_CollectionChanged); } private void AddItems(IEnumerable<TSource> items) { foreach (var sourceItem in items) { Add(_converter(sourceItem)); } } void _source_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) { switch (e.Action) { case NotifyCollectionChangedAction.Add: AddItems(e.NewItems.Cast<TSource>()); break; case NotifyCollectionChangedAction.Move: // Not sure what to do here... break; case NotifyCollectionChangedAction.Remove: foreach (var sourceItem in e.OldItems.Cast<TSource>()) { var toRemove = this.First(item => _isSameSource(item, sourceItem)); this.Remove(toRemove); } break; case NotifyCollectionChangedAction.Replace: for (int i = e.NewStartingIndex; i < e.NewItems.Count; i++) { this[i] = _converter((TSource)e.NewItems[i]); } break; case NotifyCollectionChangedAction.Reset: this.Clear(); this.AddItems(_source); break; default: break; } } } </code></pre> <p>Use it as follows :</p> <pre><code>var models = new ObservableCollection<Model>(); var viewModels = new BoundObservableCollection<ViewModel, Model>( models, m => new ViewModel(m), // creates a ViewModel from a Model (vm, m) => vm.Model.Equals(m)); // checks if the ViewModel corresponds to the specified model </code></pre> <p>The <code>BoundObservableCollection</code> will be updated when the <code>ObservableCollection</code> will change, but not the other way around (you would have to override a few methods to do that)</p>

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