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copied!<p>Added to TruelyObservableCollection event "ItemPropertyChanged":</p> <pre><code>using System; using System.Collections.Generic; using System.Collections.ObjectModel; // ObservableCollection using System.ComponentModel; // INotifyPropertyChanged using System.Collections.Specialized; // NotifyCollectionChangedEventHandler using System.Linq; using System.Text; using System.Threading.Tasks; namespace ObservableCollectionTest { class Program { static void Main(string[] args) { // ATTN: Please note it's a "TrulyObservableCollection" that's instantiated. Otherwise, "Trades[0].Qty = 999" will NOT trigger event handler "Trades_CollectionChanged" in main. // REF: http://stackoverflow.com/questions/8490533/notify-observablecollection-when-item-changes TrulyObservableCollection<Trade> Trades = new TrulyObservableCollection<Trade>(); Trades.Add(new Trade { Symbol = "APPL", Qty = 123 }); Trades.Add(new Trade { Symbol = "IBM", Qty = 456}); Trades.Add(new Trade { Symbol = "CSCO", Qty = 789 }); Trades.CollectionChanged += Trades_CollectionChanged; Trades.ItemPropertyChanged += PropertyChangedHandler; Trades.RemoveAt(2); Trades[0].Qty = 999; Console.WriteLine("Hit any key to exit"); Console.ReadLine(); return; } static void PropertyChangedHandler(object sender, PropertyChangedEventArgs e) { Console.WriteLine(DateTime.Now.ToString() + ", Property changed: " + e.PropertyName + ", Symbol: " + ((Trade) sender).Symbol + ", Qty: " + ((Trade) sender).Qty); return; } static void Trades_CollectionChanged(object sender, EventArgs e) { Console.WriteLine(DateTime.Now.ToString() + ", Collection changed"); return; } } #region TrulyObservableCollection public class TrulyObservableCollection<T> : ObservableCollection<T> where T : INotifyPropertyChanged { public event PropertyChangedEventHandler ItemPropertyChanged; public TrulyObservableCollection() : base() { CollectionChanged += new NotifyCollectionChangedEventHandler(TrulyObservableCollection_CollectionChanged); } void TrulyObservableCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e) { if (e.NewItems != null) { foreach (Object item in e.NewItems) { (item as INotifyPropertyChanged).PropertyChanged += new PropertyChangedEventHandler(item_PropertyChanged); } } if (e.OldItems != null) { foreach (Object item in e.OldItems) { (item as INotifyPropertyChanged).PropertyChanged -= new PropertyChangedEventHandler(item_PropertyChanged); } } } void item_PropertyChanged(object sender, PropertyChangedEventArgs e) { NotifyCollectionChangedEventArgs a = new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset); OnCollectionChanged(a); if (ItemPropertyChanged != null) { ItemPropertyChanged(sender, e); } } } #endregion #region Sample entity class Trade : INotifyPropertyChanged { protected string _Symbol; protected int _Qty = 0; protected DateTime _OrderPlaced = DateTime.Now; public DateTime OrderPlaced { get { return _OrderPlaced; } } public string Symbol { get { return _Symbol; } set { _Symbol = value; NotifyPropertyChanged("Symbol"); } } public int Qty { get { return _Qty; } set { _Qty = value; NotifyPropertyChanged("Qty"); } } public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(String propertyName = "") { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } } #endregion } </code></pre>

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