Observablecollection: appelant oncollectionchangted avec plusieurs nouveaux articles

Merci pour l'inspiration andyp. J'ai eu quelques problèmes avec votre implémentation, tels que l'utilisation de CollectionView au lieu d'IcollectionView dans le test et appelant manuellement "réinitialiser" sur les éléments. Les éléments qui hériter de CollectionView pourraient réellement traiter ces arguments de manière à d'autres moyens que d'appeler «cela.ReSet ()», il est donc préférable de toujours tirer leurs gestionnaires, juste avec l'action = réinitialiser arguments qu'ils ont besoin au lieu de l'amélioration de l'événement que Inclure la liste des éléments modifiés. Vous trouverez ci-dessous ma mise en œuvre (très similaire).

public class BaseObservableCollection<T> : ObservableCollection<T>
{
    //Flag used to prevent OnCollectionChanged from firing during a bulk operation like Add(IEnumerable<T>) and Clear()
    private bool _SuppressCollectionChanged = false;

    /// Overridden so that we may manually call registered handlers and differentiate between those that do and don't require Action.Reset args.
    public override event NotifyCollectionChangedEventHandler CollectionChanged;

    public BaseObservableCollection() : base(){}
    public BaseObservableCollection(IEnumerable<T> data) : base(data){}

    #region Event Handlers
    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        if( !_SuppressCollectionChanged )
        {
            base.OnCollectionChanged(e);
            if( CollectionChanged != null )
                CollectionChanged.Invoke(this, e);
        }
    }

    //CollectionViews raise an error when they are passed a NotifyCollectionChangedEventArgs that indicates more than
    //one element has been added or removed. They prefer to receive a "Action=Reset" notification, but this is not suitable
    //for applications in code, so we actually check the type we're notifying on and pass a customized event args.
    protected virtual void OnCollectionChangedMultiItem(NotifyCollectionChangedEventArgs e)
    {
        NotifyCollectionChangedEventHandler handlers = this.CollectionChanged;
        if( handlers != null )
            foreach( NotifyCollectionChangedEventHandler handler in handlers.GetInvocationList() )
                handler(this, !(handler.Target is ICollectionView) ? e : new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
    }
    #endregion

    #region Extended Collection Methods
    protected override void ClearItems()
    {
        if( this.Count == 0 ) return;

        List<T> removed = new List<T>(this);
        _SuppressCollectionChanged = true;
        base.ClearItems();
        _SuppressCollectionChanged = false;
        OnCollectionChangedMultiItem(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, removed));
    }

    public void Add(IEnumerable<T> toAdd)
    {
        if( this == toAdd )
            throw new Exception("Invalid operation. This would result in iterating over a collection as it is being modified.");

        _SuppressCollectionChanged = true;
        foreach( T item in toAdd )
            Add(item);
        _SuppressCollectionChanged = false;
        OnCollectionChangedMultiItem(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, new List<T>(toAdd)));
    }

    public void Remove(IEnumerable<T> toRemove)
    {
        if( this == toRemove )
            throw new Exception("Invalid operation. This would result in iterating over a collection as it is being modified.");

        _SuppressCollectionChanged = true;
        foreach( T item in toRemove )
            Remove(item);
        _SuppressCollectionChanged = false;
        OnCollectionChangedMultiItem(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, new List<T>(toRemove)));
    }
    #endregion
}

Après de nombreuses itérations, nous avons fini par cette version de observablerangecollection code> et readonlyobservablerangecollection code> qui est basé sur le code de la réponse acceptée et que nous n'avions pas eu à Modifier au cours des 6 derniers mois:

public class ObservableRangeCollection<T> : ObservableCollection<T>
{
    private bool suppressNotification;

    public ObservableRangeCollection() { }

    public ObservableRangeCollection(IEnumerable<T> items)
        : base(items)
    {
    }

    public override event NotifyCollectionChangedEventHandler CollectionChanged;

    protected virtual void OnCollectionChangedMultiItem(
        NotifyCollectionChangedEventArgs e)
    {
        var handlers = CollectionChanged;
        if (handlers == null) return;

        foreach (NotifyCollectionChangedEventHandler handler in handlers.GetInvocationList())
        {
            if (handler.Target is ReadOnlyObservableCollection<T>
                && !(handler.Target is ReadOnlyObservableRangeCollection<T>))
            {
                throw new NotSupportedException(
                    "ObservableRangeCollection is wrapped in ReadOnlyObservableCollection which might be bound to ItemsControl " +
                    "which is internally using ListCollectionView which does not support range actions.\n" +
                    "Instead of ReadOnlyObservableCollection, use ReadOnlyObservableRangeCollection");
            }
            var collectionView = handler.Target as ICollectionView;
            if (collectionView != null)
            {
                collectionView.Refresh();
            }
            else
            {
                handler(this, e);
            }
        }
    }

    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        if (suppressNotification) return;

        base.OnCollectionChanged(e);
        if (CollectionChanged != null)
        {
            CollectionChanged.Invoke(this, e);
        }
    }

    public void AddRange(IEnumerable<T> items)
    {
        if (items == null) return;

        suppressNotification = true;

        var itemList = items.ToList();

        foreach (var item in itemList)
        {
            Add(item);
        }
        suppressNotification = false;

        if (itemList.Any())
        {
            OnCollectionChangedMultiItem(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, itemList));
        }
    }

    public void AddRange(params T[] items)
    {
        AddRange((IEnumerable<T>)items);
    }

    public void ReplaceWithRange(IEnumerable<T> items)
    {
        Items.Clear();
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        AddRange(items);
    }

    public void RemoveRange(IEnumerable<T> items)
    {
        suppressNotification = true;

        var removableItems = items.Where(x => Items.Contains(x)).ToList();

        foreach (var item in removableItems)
        {
            Remove(item);
        }

        suppressNotification = false;

        if (removableItems.Any())
        {
            OnCollectionChangedMultiItem(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, removableItems));
        }
    }
}

public class ReadOnlyObservableRangeCollection<T> : ReadOnlyObservableCollection<T>
{
    public ReadOnlyObservableRangeCollection(ObservableCollection<T> list)
        : base(list)
    {            
    }

    protected override event NotifyCollectionChangedEventHandler CollectionChanged;

    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        var handlers = CollectionChanged;
        if (handlers == null) return;

        foreach (NotifyCollectionChangedEventHandler handler in handlers.GetInvocationList())
        {
            var collectionView = handler.Target as ICollectionView;
            if (collectionView != null)
            {
                collectionView.Refresh();
            }
            else
            {
                handler(this, e);
            }
        }
    }
}