Observable Stack and Queue

Question

I\'m looking for an INotifyCollectionChanged implementation of Stack and Queue. I could roll my own but I don\'t want to reinvent the

Answer 1

I realize there are already a few answers but figured I would give back a little with mine. I put together everything mentioned in the posts and comments. There were few things that motivated me to do this:

• INPC should always fire for Count when Push, Pop, or Clear are called, as mentioned in one of the posts.
• For Clear, action should be Reset and index for the collection change event should be set to -1 (which it will default to anyway if not set so the other posts have that): .NET docs
• For Push/Pop, action should be Add/Remove and index for the collection changed event should be 0 for a stack being that it is always and only the first item that can be maniuplated (think stack.GetEnumerator().MoveNext()).
• Exposed all 3 constructors available in Stack and use base() calls since there is no reason to override the logic.

Results in:

public class ObservableStack : Stack, INotifyCollectionChanged, INotifyPropertyChanged
{
    #region Constructors

    public ObservableStack() : base() { }

    public ObservableStack(IEnumerable collection) : base(collection) { }

    public ObservableStack(int capacity) : base(capacity) { }

    #endregion

    #region Overrides

    public virtual new T Pop()
    {
        var item = base.Pop();
        OnCollectionChanged(NotifyCollectionChangedAction.Remove, item);

        return item;
    }

    public virtual new void Push(T item)
    {
        base.Push(item);
        OnCollectionChanged(NotifyCollectionChangedAction.Add, item);
    }

    public virtual new void Clear()
    {
        base.Clear();
        OnCollectionChanged(NotifyCollectionChangedAction.Reset, default);
    }

    #endregion

    #region CollectionChanged

    public virtual event NotifyCollectionChangedEventHandler CollectionChanged;

    protected virtual void OnCollectionChanged(NotifyCollectionChangedAction action, T item)
    {
        CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(
            action
            , item
            , item == null ? -1 : 0)
        );

        OnPropertyChanged(nameof(Count));
    }

    #endregion

    #region PropertyChanged

    public virtual event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string proertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(proertyName));
    }

    #endregion
}