can two collection in wpf have same objects
using System;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Linq;
using System.Windows.Input;
namespace WpfApplication1
{
public class ViewModel
{
private readonly ObservableCollection<Item> _clone;
private readonly ObservableCollection<Item> _source;
private readonly Collection<Item> _changes = new Collection<Item>();
public ViewModel(ObservableCollection<Item> items)
{
_source = items;
_clone = new ObservableCollection<Item>(items);
_clone.CollectionChanged += clone_CollectionChanged;
}
void clone_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
foreach (var newItem in e.NewItems.Cast<Item>())
{
_changes.Add(newItem);
}
break;
}
}
public ObservableCollection<Item> Clone
{
get { return _clone; }
}
private DelegateCommand _commitChangesCommand;
public ICommand CommitChangesCommand
{
get { return _commitChangesCommand ?? (_commitChangesCommand = new DelegateCommand(CommitChanges, CanCommitChanges)); }
}
private void CommitChanges(object sender)
{
foreach (var change in _changes)
{
_source.Add(change);
}
_changes.Clear();
}
private bool CanCommitChanges(object sender)
{
return _changes.Any();
}
}
public class Item
{
}
public class DelegateCommand : ICommand
{
private readonly Predicate<object> _canExecute;
private readonly Action<object> _execute;
public event EventHandler CanExecuteChanged;
public DelegateCommand(Action<object> execute)
: this(execute, null)
{
}
public DelegateCommand(Action<object> execute,
Predicate<object> canExecute)
{
_execute = execute;
_canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
return _canExecute == null || _canExecute(parameter);
}
public void Execute(object parameter)
{
_execute(parameter);
}
public void RaiseCanExecuteChanged()
{
if (CanExecuteChanged != null)
{
CanExecuteChanged(this, EventArgs.Empty);
}
}
}
}