BulkUpdateObservableCollection.cs

using System;
using System.Collections.ObjectModel;
using System.Linq;
using System.Collections.Specialized;
using System.Timers;
namespace System.Collections.Generic {
	public class BulkUpdateObservableCollection<T> : ObservableCollection<T> {
		bool isBulkUpdating;

		protected override void OnCollectionChanged (NotifyCollectionChangedEventArgs e)
		{
			if (!isBulkUpdating)
				base.OnCollectionChanged (e);
		}
		Timer searchTimer;
		List<T> batchItems = new List<T> ();
		public void AddBatch (T item)
		{
			lock (batchItems)
				batchItems.Add (item);
			if (searchTimer == null) {
				searchTimer = new Timer (100);
				searchTimer.Elapsed += (s, e) => {
					lock (batchItems) {
						var items = batchItems.ToList ();
						batchItems.Clear ();
						AddRange (items);
					}
				};
			} else
				searchTimer.Stop ();
			searchTimer.Start ();
		}

		public void Replace (IEnumerable<T> items)
		{
			if (!items?.Any () ?? false) {
				Clear ();
				return;
			}
			isBulkUpdating = true;
			Clear ();

			foreach (var item in items)
				Add (item);
			isBulkUpdating = false;
			OnCollectionChanged (new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Reset));
		}
		public void AddRange (IEnumerable<T> items)
		{
			if (!items?.Any () ?? false) {
				return;
			}

			isBulkUpdating = true;
			var startingIndex = items.Count ();
			foreach (var item in items)
				Add (item);
			isBulkUpdating = false;
			OnCollectionChanged (new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Add, items.ToList ()));
		}
		public void Remove (IEnumerable<T> items)
		{
			if (!items?.Any () ?? false) {
				return;
			}

			isBulkUpdating = true;
			var startingIndex = items.Count ();
			foreach (var item in items)
				Remove (item);
			isBulkUpdating = false;
			OnCollectionChanged (new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Remove, items.ToList ()));
		}
	}
}