c# - Can I somehow temporarily disable WPF data binding changes?

Question

I have a WPF application that uses MVVM data bindings. I am adding items to an ObservableCollection<...> and quite many of them indeed.

Now I am wondering that every time I add one to the collection, does it instantly fire the event and cause unnecessary overhead? If so, can I somehow temporarily disable the event notifications and manually fire it once at the end of my code so that if I add 10k items, it gets only fired once, rather than 10k times?

Update: I tried having this class:

using System;
using System.Linq;
using System.Collections.Specialized;
using System.Collections.Generic;

namespace MyProject
{

    /// <summary> 
    /// Represents a dynamic data collection that provides notifications when items get added, removed, or when the whole list is refreshed. 
    /// </summary> 
    /// <typeparam name="T"></typeparam> 
    public class ObservableCollection<T> : System.Collections.ObjectModel.ObservableCollection<T>
    {

        /// <summary> 
        /// Adds the elements of the specified collection to the end of the ObservableCollection(Of T). 
        /// </summary> 
        public void AddRange(IEnumerable<T> collection)
        {
            foreach (var i in collection) Items.Add(i);
            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, collection.ToList()));
        }

        /// <summary> 
        /// Removes the first occurence of each item in the specified collection from ObservableCollection(Of T). 
        /// </summary> 
        public void RemoveRange(IEnumerable<T> collection)
        {
            foreach (var i in collection) Items.Remove(i);
            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, collection.ToList()));
        }

        /// <summary> 
        /// Clears the current collection and replaces it with the specified item. 
        /// </summary> 
        public void Replace(T item)
        {
            ReplaceRange(new T[] { item });
        }
        /// <summary> 
        /// Clears the current collection and replaces it with the specified collection. 
        /// </summary> 
        public void ReplaceRange(IEnumerable<T> collection)
        {
            List<T> old = new List<T>(Items);
            Items.Clear();
            foreach (var i in collection) Items.Add(i);
            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, collection.ToList()));
        }

        /// <summary> 
        /// Initializes a new instance of the System.Collections.ObjectModel.ObservableCollection(Of T) class. 
        /// </summary> 
        public ObservableCollection() : base() { }

        /// <summary> 
        /// Initializes a new instance of the System.Collections.ObjectModel.ObservableCollection(Of T) class that contains elements copied from the specified collection. 
        /// </summary> 
        /// <param name="collection">collection: The collection from which the elements are copied.</param> 
        /// <exception cref="System.ArgumentNullException">The collection parameter cannot be null.</exception> 
        public ObservableCollection(IEnumerable<T> collection) : base(collection) { }
    }
}

I get this error now:

Additional information: Range actions are not supported.

The error comes here:

OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, collection.ToList()));

Answer 1

This extension of ObservableCollection solves the problem easily.

It exposes a public SupressNotification property to allow the user to control when CollectionChanged notification will be suppressed.

It does not offer range insertion/deletion, but if CollectionChanged notification is suppressed, the need to do range operation on the collection diminishes in most of the cases.

This implementation substitutes all suppressed notifications with a Reset notification. This is logically sensible. When the user suppresses the notification, do bulk changes and then re-enable it, it should appropriate to send a Resent notification.

public class ObservableCollectionEx<T> : ObservableCollection<T>
{
    private bool _notificationSupressed = false;
    private bool _supressNotification = false;
    public bool SupressNotification
    {
        get
        {
            return _supressNotification;
        }
        set
        {
            _supressNotification = value;
            if (_supressNotification == false && _notificationSupressed)
            {
                this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
                _notificationSupressed = false;
            }
        }
    }

    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        if (SupressNotification)
        {
            _notificationSupressed = true;
            return;
        }
        base.OnCollectionChanged(e);
    }
}