ObservableCollection Doesn't support AddRange method, so I get notified for each item added, besides what about INotifyCollectionChanging?

Question

I want to be able to add a range and get updated for the entire bulk.

I also want to be able to cancel the action before it's done (i.e. collection changing besides the 'changed').

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Related Q Which .Net collection for adding multiple objects at once and getting notified?

Answer 1

Please refer to the updated and optimized C# 7 version. I didn't want to remove the VB.NET version so I just posted it in a separate answer.

Go to updated version

Seems it's not supported, I implemented by myself, FYI, hope it to be helpful:

I updated the VB version and from now on it raises an event before changing the collection so you can regret (useful when using with DataGrid, ListView and many more, that you can show an "Are you sure" confirmation to the user), the updated VB version is in the bottom of this message.

Please accept my apology that the screen is too narrow to contain my code, I don't like it either.

VB.NET:

Imports System.Collections.Specialized  Namespace System.Collections.ObjectModel     ''' <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 ObservableRangeCollection(Of T) : Inherits System.Collections.ObjectModel.ObservableCollection(Of T)          ''' <summary>         ''' Adds the elements of the specified collection to the end of the ObservableCollection(Of T).         ''' </summary>         Public Sub AddRange(ByVal collection As IEnumerable(Of T))             For Each i In collection                 Items.Add(i)             Next             OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))         End Sub          ''' <summary>         ''' Removes the first occurence of each item in the specified collection from ObservableCollection(Of T).         ''' </summary>         Public Sub RemoveRange(ByVal collection As IEnumerable(Of T))             For Each i In collection                 Items.Remove(i)             Next              OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))         End Sub          ''' <summary>         ''' Clears the current collection and replaces it with the specified item.         ''' </summary>         Public Sub Replace(ByVal item As T)             ReplaceRange(New T() {item})         End Sub         ''' <summary>         ''' Clears the current collection and replaces it with the specified collection.         ''' </summary>         Public Sub ReplaceRange(ByVal collection As IEnumerable(Of T))             Dim old = Items.ToList             Items.Clear()             For Each i In collection                 Items.Add(i)             Next             OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))         End Sub          ''' <summary>         ''' Initializes a new instance of the System.Collections.ObjectModel.ObservableCollection(Of T) class.         ''' </summary>         ''' <remarks></remarks>         Public Sub New()             MyBase.New()         End Sub         ''' <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 Sub New(ByVal collection As IEnumerable(Of T))             MyBase.New(collection)         End Sub     End Class     End Namespace 

C#:

using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Collections.Specialized; using System.Linq;  /// <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 ObservableRangeCollection<T> : 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)     {         if (collection == null) throw new ArgumentNullException("collection");          foreach (var i in collection) Items.Add(i);         OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));     }      /// <summary>      /// Removes the first occurence of each item in the specified collection from ObservableCollection(Of T).      /// </summary>      public void RemoveRange(IEnumerable<T> collection)     {         if (collection == null) throw new ArgumentNullException("collection");          foreach (var i in collection) Items.Remove(i);         OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));     }      /// <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)     {         if (collection == null) throw new ArgumentNullException("collection");          Items.Clear();         foreach (var i in collection) Items.Add(i);         OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));     }      /// <summary>      /// Initializes a new instance of the System.Collections.ObjectModel.ObservableCollection(Of T) class.      /// </summary>      public ObservableRangeCollection()         : 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 ObservableRangeCollection(IEnumerable<T> collection)         : base(collection) { } } 

Update - Observable range collection with collection changing notification

Imports System.Collections.Specialized Imports System.ComponentModel Imports System.Collections.ObjectModel  Public Class ObservableRangeCollection(Of T) : Inherits ObservableCollection(Of T) : Implements INotifyCollectionChanging(Of T)     ''' <summary>     ''' Initializes a new instance of the System.Collections.ObjectModel.ObservableCollection(Of T) class.     ''' </summary>     ''' <remarks></remarks>     Public Sub New()         MyBase.New()     End Sub      ''' <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 Sub New(ByVal collection As IEnumerable(Of T))         MyBase.New(collection)     End Sub      ''' <summary>     ''' Adds the elements of the specified collection to the end of the ObservableCollection(Of T).     ''' </summary>     Public Sub AddRange(ByVal collection As IEnumerable(Of T))         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Add, collection)         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          Dim index = Items.Count - 1         For Each i In collection             Items.Add(i)         Next          OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, collection, index))     End Sub       ''' <summary>     ''' Inserts the collection at specified index.     ''' </summary>     Public Sub InsertRange(ByVal index As Integer, ByVal Collection As IEnumerable(Of T))         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Add, Collection)         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          For Each i In Collection             Items.Insert(index, i)         Next          OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))     End Sub       ''' <summary>     ''' Removes the first occurence of each item in the specified collection from ObservableCollection(Of T).     ''' </summary>     Public Sub RemoveRange(ByVal collection As IEnumerable(Of T))         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Remove, collection)         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          For Each i In collection             Items.Remove(i)         Next          OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))     End Sub        ''' <summary>     ''' Clears the current collection and replaces it with the specified item.     ''' </summary>     Public Sub Replace(ByVal item As T)         ReplaceRange(New T() {item})     End Sub      ''' <summary>     ''' Clears the current collection and replaces it with the specified collection.     ''' </summary>     Public Sub ReplaceRange(ByVal collection As IEnumerable(Of T))         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Replace, Items)         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          Items.Clear()         For Each i In collection             Items.Add(i)         Next         OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))     End Sub      Protected Overrides Sub ClearItems()         Dim e As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Reset, Items)         OnCollectionChanging(e)          If e.Cancel Then Exit Sub          MyBase.ClearItems()     End Sub      Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As T)         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Add, item)         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          MyBase.InsertItem(index, item)     End Sub      Protected Overrides Sub MoveItem(ByVal oldIndex As Integer, ByVal newIndex As Integer)         Dim ce As New NotifyCollectionChangingEventArgs(Of T)()         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          MyBase.MoveItem(oldIndex, newIndex)     End Sub      Protected Overrides Sub RemoveItem(ByVal index As Integer)         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Remove, Items(index))         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          MyBase.RemoveItem(index)     End Sub      Protected Overrides Sub SetItem(ByVal index As Integer, ByVal item As T)         Dim ce As New NotifyCollectionChangingEventArgs(Of T)(NotifyCollectionChangedAction.Replace, Items(index))         OnCollectionChanging(ce)         If ce.Cancel Then Exit Sub          MyBase.SetItem(index, item)     End Sub      Protected Overrides Sub OnCollectionChanged(ByVal e As Specialized.NotifyCollectionChangedEventArgs)         If e.NewItems IsNot Nothing Then             For Each i As T In e.NewItems                 If TypeOf i Is INotifyPropertyChanged Then AddHandler DirectCast(i, INotifyPropertyChanged).PropertyChanged, AddressOf Item_PropertyChanged             Next         End If         MyBase.OnCollectionChanged(e)     End Sub      Private Sub Item_PropertyChanged(ByVal sender As T, ByVal e As ComponentModel.PropertyChangedEventArgs)         OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset, sender, IndexOf(sender)))     End Sub      Public Event CollectionChanging(ByVal sender As Object, ByVal e As NotifyCollectionChangingEventArgs(Of T)) Implements INotifyCollectionChanging(Of T).CollectionChanging     Protected Overridable Sub OnCollectionChanging(ByVal e As NotifyCollectionChangingEventArgs(Of T))         RaiseEvent CollectionChanging(Me, e)     End Sub End Class   Public Interface INotifyCollectionChanging(Of T)     Event CollectionChanging(ByVal sender As Object, ByVal e As NotifyCollectionChangingEventArgs(Of T)) End Interface  Public Class NotifyCollectionChangingEventArgs(Of T) : Inherits CancelEventArgs      Public Sub New()         m_Action = NotifyCollectionChangedAction.Move         m_Items = New T() {}     End Sub      Public Sub New(ByVal action As NotifyCollectionChangedAction, ByVal item As T)         m_Action = action         m_Items = New T() {item}     End Sub      Public Sub New(ByVal action As NotifyCollectionChangedAction, ByVal items As IEnumerable(Of T))         m_Action = action         m_Items = items     End Sub      Private m_Action As NotifyCollectionChangedAction     Public ReadOnly Property Action() As NotifyCollectionChangedAction         Get             Return m_Action         End Get     End Property      Private m_Items As IList     Public ReadOnly Property Items() As IEnumerable(Of T)         Get             Return m_Items         End Get     End Property End Class