আমি একটি পরিসীমা যুক্ত করতে এবং পুরো বালকের জন্য আপডেট হতে চাই।
আমি ক্রিয়াটি সম্পন্ন করার আগে (যেমন 'পরিবর্তিত'র পরিবর্তে সংগ্রহ পরিবর্তন করা) বাতিল করতে সক্ষম হতে চাই।
সম্পর্কিত প্রশ্ন একবারে একাধিক অবজেক্ট যুক্ত করার জন্য এবং বিজ্ঞপ্তি পাওয়ার জন্য নেট সংগ্রহ?
উত্তর:
দয়া করে আপডেট ও অপ্টিমাইজড সি # 7 সংস্করণটি দেখুন । আমি VB.NET সংস্করণটি সরাতে চাইনি তাই আমি এটি একটি পৃথক উত্তরে পোস্ট করেছি।
দেখে মনে হচ্ছে এটি সমর্থিত নয়, আমি নিজে দ্বারা প্রয়োগ করেছি, এফওয়াইআই, আশা করি এটি সহায়ক হবে:
আমি ভিবি সংস্করণ এবং এখন থেকে এটা সংগ্রহ পরিবর্তন যাতে আপনি দু: খ প্রকাশ করতে পারার আগে একটি ঘটনা উত্থাপন আপডেট (দরকারী যখন এর মাধ্যমে ব্যবহার DataGrid, ListViewএবং আরো অনেক, আপনি একটি "আপনি কি নিশ্চিত" ব্যবহারকারীর এ নিশ্চিতকরণ দেখাতে পারেন), আপডেট ভিবি সংস্করণটি এই বার্তার নীচে রয়েছে ।
আমার কোডটি ধারণ করার জন্য স্ক্রিনটি খুব সংকীর্ণ বলে আমার ক্ষমা প্রার্থনা করুন I
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 Namespaceসি #:
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) { }
}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 ClassOnPropertyChanged("Count");এবং OnPropertyChanged("Item[]");সম্পূর্ণরূপে মান ObservableCollection Mimik করার অ্যাড / Remove মধ্যে / ব্যাপ্তি পদ্ধতি প্রতিস্থাপন করুন।
প্রথমত, দয়া করে ভোট দিন এবং .NET রেপোতে এপিআই অনুরোধটি সম্পর্কে মন্তব্য করুন ।
এখানে আমার অপটিমাইজড সংস্করণটি ObservableRangeCollection(জেমস মন্টেম্যাগনোর একটির অনুকূলিত সংস্করণ )।
এটি খুব দ্রুত সম্পাদন করে এবং যখন সম্ভব হয় তখন বিদ্যমান উপাদানগুলিকে পুনরায় ব্যবহার করা এবং অপ্রয়োজনীয় ইভেন্টগুলি এড়ানো বা যখন সম্ভব হয় তখন এগুলিতে ব্যাচিংয়ের উদ্দেশ্য। ReplaceRangeপদ্ধতি প্রতিস্থাপন / অপসারণ / উপযুক্ত সূচক এবং ব্যাচ সম্ভব ঘটনা দ্বারা প্রয়োজন উপাদান যোগ করে।
জ্যামারিন.ফর্মস ইউআইতে পরীক্ষা করা হয়েছে বড় সংগ্রহের প্রতি ঘন ঘন আপডেটের জন্য দুর্দান্ত ফলাফল (প্রতি সেকেন্ডে 5-7 আপডেট)।
দ্রষ্টব্য: যেহেতু ডাব্লুপিএফ পরিসীমা অপারেশনগুলির সাথে কাজ করতে অভ্যস্ত নয়, তাই ডাব্লুপিএফ ইউআই-সম্পর্কিত কাজে যেমন নীচের NotSupportedExceptionদিক ObservableRangeCollectionথেকে এটি ব্যবহার করে ListBoxইত্যাদি ব্যবহার করার সময় এটি নিক্ষেপ করবে (আপনি এখনও ObservableRangeCollection<T>ইউআই-তে আবদ্ধ না হলে এটি ব্যবহার করতে পারেন) ।
তবে আপনি WpfObservableRangeCollection<T>workaround ব্যবহার করতে পারেন ।
আসল সমাধানটি এমন একটি তৈরি করা হবে CollectionViewযা জানে কীভাবে পরিসীমা অপারেশনগুলি মোকাবেলা করতে হয়, তবে এখনও আমার এটিকে বাস্তবায়নের সময় হয়নি।
RAW কোড - কাঁচা হিসাবে খুলুন, তারপরেসমস্ত নির্বাচনকরতেCtrl+Aকরুন, তারপরেCtrl+Cঅনুলিপি করুন।
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections.Generic;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
namespace System.Collections.ObjectModel
{
/// <summary>
/// Implementation of a dynamic data collection based on generic Collection<T>,
/// implementing INotifyCollectionChanged to notify listeners
/// when items get added, removed or the whole list is refreshed.
/// </summary>
public class ObservableRangeCollection<T> : ObservableCollection<T>
{
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
[NonSerialized]
private DeferredEventsCollection _deferredEvents;
#endregion Private Fields
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
/// <summary>
/// Initializes a new instance of ObservableCollection that is empty and has default initial capacity.
/// </summary>
public ObservableRangeCollection() { }
/// <summary>
/// Initializes a new instance of the ObservableCollection class that contains
/// elements copied from the specified collection and has sufficient capacity
/// to accommodate the number of elements copied.
/// </summary>
/// <param name="collection">The collection whose elements are copied to the new list.</param>
/// <remarks>
/// The elements are copied onto the ObservableCollection in the
/// same order they are read by the enumerator of the collection.
/// </remarks>
/// <exception cref="ArgumentNullException"> collection is a null reference </exception>
public ObservableRangeCollection(IEnumerable<T> collection) : base(collection) { }
/// <summary>
/// Initializes a new instance of the ObservableCollection class
/// that contains elements copied from the specified list
/// </summary>
/// <param name="list">The list whose elements are copied to the new list.</param>
/// <remarks>
/// The elements are copied onto the ObservableCollection in the
/// same order they are read by the enumerator of the list.
/// </remarks>
/// <exception cref="ArgumentNullException"> list is a null reference </exception>
public ObservableRangeCollection(List<T> list) : base(list) { }
#endregion Constructors
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Adds the elements of the specified collection to the end of the <see cref="ObservableCollection{T}"/>.
/// </summary>
/// <param name="collection">
/// The collection whose elements should be added to the end of the <see cref="ObservableCollection{T}"/>.
/// The collection itself cannot be null, but it can contain elements that are null, if type T is a reference type.
/// </param>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
public void AddRange(IEnumerable<T> collection)
{
InsertRange(Count, collection);
}
/// <summary>
/// Inserts the elements of a collection into the <see cref="ObservableCollection{T}"/> at the specified index.
/// </summary>
/// <param name="index">The zero-based index at which the new elements should be inserted.</param>
/// <param name="collection">The collection whose elements should be inserted into the List<T>.
/// The collection itself cannot be null, but it can contain elements that are null, if type T is a reference type.</param>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is not in the collection range.</exception>
public void InsertRange(int index, IEnumerable<T> collection)
{
if (collection == null)
throw new ArgumentNullException(nameof(collection));
if (index < 0)
throw new ArgumentOutOfRangeException(nameof(index));
if (index > Count)
throw new ArgumentOutOfRangeException(nameof(index));
if (collection is ICollection<T> countable)
{
if (countable.Count == 0)
{
return;
}
}
else if (!ContainsAny(collection))
{
return;
}
CheckReentrancy();
//expand the following couple of lines when adding more constructors.
var target = (List<T>)Items;
target.InsertRange(index, collection);
OnEssentialPropertiesChanged();
if (!(collection is IList list))
list = new List<T>(collection);
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, list, index));
}
/// <summary>
/// Removes the first occurence of each item in the specified collection from the <see cref="ObservableCollection{T}"/>.
/// </summary>
/// <param name="collection">The items to remove.</param>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
public void RemoveRange(IEnumerable<T> collection)
{
if (collection == null)
throw new ArgumentNullException(nameof(collection));
if (Count == 0)
{
return;
}
else if (collection is ICollection<T> countable)
{
if (countable.Count == 0)
return;
else if (countable.Count == 1)
using (IEnumerator<T> enumerator = countable.GetEnumerator())
{
enumerator.MoveNext();
Remove(enumerator.Current);
return;
}
}
else if (!(ContainsAny(collection)))
{
return;
}
CheckReentrancy();
var clusters = new Dictionary<int, List<T>>();
var lastIndex = -1;
List<T> lastCluster = null;
foreach (T item in collection)
{
var index = IndexOf(item);
if (index < 0)
{
continue;
}
Items.RemoveAt(index);
if (lastIndex == index && lastCluster != null)
{
lastCluster.Add(item);
}
else
{
clusters[lastIndex = index] = lastCluster = new List<T> { item };
}
}
OnEssentialPropertiesChanged();
if (Count == 0)
OnCollectionReset();
else
foreach (KeyValuePair<int, List<T>> cluster in clusters)
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, cluster.Value, cluster.Key));
}
/// <summary>
/// Iterates over the collection and removes all items that satisfy the specified match.
/// </summary>
/// <remarks>The complexity is O(n).</remarks>
/// <param name="match"></param>
/// <returns>Returns the number of elements that where </returns>
/// <exception cref="ArgumentNullException"><paramref name="match"/> is null.</exception>
public int RemoveAll(Predicate<T> match)
{
return RemoveAll(0, Count, match);
}
/// <summary>
/// Iterates over the specified range within the collection and removes all items that satisfy the specified match.
/// </summary>
/// <remarks>The complexity is O(n).</remarks>
/// <param name="index">The index of where to start performing the search.</param>
/// <param name="count">The number of items to iterate on.</param>
/// <param name="match"></param>
/// <returns>Returns the number of elements that where </returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is out of range.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="count"/> is out of range.</exception>
/// <exception cref="ArgumentNullException"><paramref name="match"/> is null.</exception>
public int RemoveAll(int index, int count, Predicate<T> match)
{
if (index < 0)
throw new ArgumentOutOfRangeException(nameof(index));
if (count < 0)
throw new ArgumentOutOfRangeException(nameof(count));
if (index + count > Count)
throw new ArgumentOutOfRangeException(nameof(index));
if (match == null)
throw new ArgumentNullException(nameof(match));
if (Count == 0)
return 0;
List<T> cluster = null;
var clusterIndex = -1;
var removedCount = 0;
using (BlockReentrancy())
using (DeferEvents())
{
for (var i = 0; i < count; i++, index++)
{
T item = Items[index];
if (match(item))
{
Items.RemoveAt(index);
removedCount++;
if (clusterIndex == index)
{
Debug.Assert(cluster != null);
cluster.Add(item);
}
else
{
cluster = new List<T> { item };
clusterIndex = index;
}
index--;
}
else if (clusterIndex > -1)
{
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, cluster, clusterIndex));
clusterIndex = -1;
cluster = null;
}
}
if (clusterIndex > -1)
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, cluster, clusterIndex));
}
if (removedCount > 0)
OnEssentialPropertiesChanged();
return removedCount;
}
/// <summary>
/// Removes a range of elements from the <see cref="ObservableCollection{T}"/>>.
/// </summary>
/// <param name="index">The zero-based starting index of the range of elements to remove.</param>
/// <param name="count">The number of elements to remove.</param>
/// <exception cref="ArgumentOutOfRangeException">The specified range is exceeding the collection.</exception>
public void RemoveRange(int index, int count)
{
if (index < 0)
throw new ArgumentOutOfRangeException(nameof(index));
if (count < 0)
throw new ArgumentOutOfRangeException(nameof(count));
if (index + count > Count)
throw new ArgumentOutOfRangeException(nameof(index));
if (count == 0)
return;
if (count == 1)
{
RemoveItem(index);
return;
}
//Items will always be List<T>, see constructors
var items = (List<T>)Items;
List<T> removedItems = items.GetRange(index, count);
CheckReentrancy();
items.RemoveRange(index, count);
OnEssentialPropertiesChanged();
if (Count == 0)
OnCollectionReset();
else
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, removedItems, index));
}
/// <summary>
/// Clears the current collection and replaces it with the specified collection,
/// using the default <see cref="EqualityComparer{T}"/>.
/// </summary>
/// <param name="collection">The items to fill the collection with, after clearing it.</param>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
public void ReplaceRange(IEnumerable<T> collection)
{
ReplaceRange(0, Count, collection, EqualityComparer<T>.Default);
}
/// <summary>
/// Clears the current collection and replaces it with the specified collection,
/// using the specified comparer to skip equal items.
/// </summary>
/// <param name="collection">The items to fill the collection with, after clearing it.</param>
/// <param name="comparer">An <see cref="IEqualityComparer{T}"/> to be used
/// to check whether an item in the same location already existed before,
/// which in case it would not be added to the collection, and no event will be raised for it.</param>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
/// <exception cref="ArgumentNullException"><paramref name="comparer"/> is null.</exception>
public void ReplaceRange(IEnumerable<T> collection, IEqualityComparer<T> comparer)
{
ReplaceRange(0, Count, collection, comparer);
}
/// <summary>
/// Removes the specified range and inserts the specified collection,
/// ignoring equal items (using <see cref="EqualityComparer{T}.Default"/>).
/// </summary>
/// <param name="index">The index of where to start the replacement.</param>
/// <param name="count">The number of items to be replaced.</param>
/// <param name="collection">The collection to insert in that location.</param>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is out of range.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="count"/> is out of range.</exception>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
public void ReplaceRange(int index, int count, IEnumerable<T> collection)
{
ReplaceRange(index, count, collection, EqualityComparer<T>.Default);
}
/// <summary>
/// Removes the specified range and inserts the specified collection in its position, leaving equal items in equal positions intact.
/// </summary>
/// <param name="index">The index of where to start the replacement.</param>
/// <param name="count">The number of items to be replaced.</param>
/// <param name="collection">The collection to insert in that location.</param>
/// <param name="comparer">The comparer to use when checking for equal items.</param>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is out of range.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="count"/> is out of range.</exception>
/// <exception cref="ArgumentNullException"><paramref name="collection"/> is null.</exception>
/// <exception cref="ArgumentNullException"><paramref name="comparer"/> is null.</exception>
public void ReplaceRange(int index, int count, IEnumerable<T> collection, IEqualityComparer<T> comparer)
{
if (index < 0)
throw new ArgumentOutOfRangeException(nameof(index));
if (count < 0)
throw new ArgumentOutOfRangeException(nameof(count));
if (index + count > Count)
throw new ArgumentOutOfRangeException(nameof(index));
if (collection == null)
throw new ArgumentNullException(nameof(collection));
if (comparer == null)
throw new ArgumentNullException(nameof(comparer));
if (collection is ICollection<T> countable)
{
if (countable.Count == 0)
{
RemoveRange(index, count);
return;
}
}
else if (!ContainsAny(collection))
{
RemoveRange(index, count);
return;
}
if (index + count == 0)
{
InsertRange(0, collection);
return;
}
if (!(collection is IList<T> list))
list = new List<T>(collection);
using (BlockReentrancy())
using (DeferEvents())
{
var rangeCount = index + count;
var addedCount = list.Count;
var changesMade = false;
List<T>
newCluster = null,
oldCluster = null;
int i = index;
for (; i < rangeCount && i - index < addedCount; i++)
{
//parallel position
T old = this[i], @new = list[i - index];
if (comparer.Equals(old, @new))
{
OnRangeReplaced(i, newCluster, oldCluster);
continue;
}
else
{
Items[i] = @new;
if (newCluster == null)
{
Debug.Assert(oldCluster == null);
newCluster = new List<T> { @new };
oldCluster = new List<T> { old };
}
else
{
newCluster.Add(@new);
oldCluster.Add(old);
}
changesMade = true;
}
}
OnRangeReplaced(i, newCluster, oldCluster);
//exceeding position
if (count != addedCount)
{
var items = (List<T>)Items;
if (count > addedCount)
{
var removedCount = rangeCount - addedCount;
T[] removed = new T[removedCount];
items.CopyTo(i, removed, 0, removed.Length);
items.RemoveRange(i, removedCount);
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, removed, i));
}
else
{
var k = i - index;
T[] added = new T[addedCount - k];
for (int j = k; j < addedCount; j++)
{
T @new = list[j];
added[j - k] = @new;
}
items.InsertRange(i, added);
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, added, i));
}
OnEssentialPropertiesChanged();
}
else if (changesMade)
{
OnIndexerPropertyChanged();
}
}
}
#endregion Public Methods
//------------------------------------------------------
//
// Protected Methods
//
//------------------------------------------------------
#region Protected Methods
/// <summary>
/// Called by base class Collection<T> when the list is being cleared;
/// raises a CollectionChanged event to any listeners.
/// </summary>
protected override void ClearItems()
{
if (Count == 0)
return;
CheckReentrancy();
base.ClearItems();
OnEssentialPropertiesChanged();
OnCollectionReset();
}
/// <summary>
/// Called by base class Collection<T> when an item is set in list;
/// raises a CollectionChanged event to any listeners.
/// </summary>
protected override void SetItem(int index, T item)
{
if (Equals(this[index], item))
return;
CheckReentrancy();
T originalItem = this[index];
base.SetItem(index, item);
OnIndexerPropertyChanged();
OnCollectionChanged(NotifyCollectionChangedAction.Replace, originalItem, item, index);
}
/// <summary>
/// Raise CollectionChanged event to any listeners.
/// Properties/methods modifying this ObservableCollection will raise
/// a collection changed event through this virtual method.
/// </summary>
/// <remarks>
/// When overriding this method, either call its base implementation
/// or call <see cref="BlockReentrancy"/> to guard against reentrant collection changes.
/// </remarks>
protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
{
if (_deferredEvents != null)
{
_deferredEvents.Add(e);
return;
}
base.OnCollectionChanged(e);
}
protected virtual IDisposable DeferEvents() => new DeferredEventsCollection(this);
#endregion Protected Methods
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
/// <summary>
/// Helper function to determine if a collection contains any elements.
/// </summary>
/// <param name="collection">The collection to evaluate.</param>
/// <returns></returns>
private static bool ContainsAny(IEnumerable<T> collection)
{
using (IEnumerator<T> enumerator = collection.GetEnumerator())
return enumerator.MoveNext();
}
/// <summary>
/// Helper to raise Count property and the Indexer property.
/// </summary>
private void OnEssentialPropertiesChanged()
{
OnPropertyChanged(EventArgsCache.CountPropertyChanged);
OnIndexerPropertyChanged();
}
/// <summary>
/// /// Helper to raise a PropertyChanged event for the Indexer property
/// /// </summary>
private void OnIndexerPropertyChanged() =>
OnPropertyChanged(EventArgsCache.IndexerPropertyChanged);
/// <summary>
/// Helper to raise CollectionChanged event to any listeners
/// </summary>
private void OnCollectionChanged(NotifyCollectionChangedAction action, object oldItem, object newItem, int index) =>
OnCollectionChanged(new NotifyCollectionChangedEventArgs(action, newItem, oldItem, index));
/// <summary>
/// Helper to raise CollectionChanged event with action == Reset to any listeners
/// </summary>
private void OnCollectionReset() =>
OnCollectionChanged(EventArgsCache.ResetCollectionChanged);
/// <summary>
/// Helper to raise event for clustered action and clear cluster.
/// </summary>
/// <param name="followingItemIndex">The index of the item following the replacement block.</param>
/// <param name="newCluster"></param>
/// <param name="oldCluster"></param>
//TODO should have really been a local method inside ReplaceRange(int index, int count, IEnumerable<T> collection, IEqualityComparer<T> comparer),
//move when supported language version updated.
private void OnRangeReplaced(int followingItemIndex, ICollection<T> newCluster, ICollection<T> oldCluster)
{
if (oldCluster == null || oldCluster.Count == 0)
{
Debug.Assert(newCluster == null || newCluster.Count == 0);
return;
}
OnCollectionChanged(
new NotifyCollectionChangedEventArgs(
NotifyCollectionChangedAction.Replace,
new List<T>(newCluster),
new List<T>(oldCluster),
followingItemIndex - oldCluster.Count));
oldCluster.Clear();
newCluster.Clear();
}
#endregion Private Methods
//------------------------------------------------------
//
// Private Types
//
//------------------------------------------------------
#region Private Types
private sealed class DeferredEventsCollection : List<NotifyCollectionChangedEventArgs>, IDisposable
{
private readonly ObservableRangeCollection<T> _collection;
public DeferredEventsCollection(ObservableRangeCollection<T> collection)
{
Debug.Assert(collection != null);
Debug.Assert(collection._deferredEvents == null);
_collection = collection;
_collection._deferredEvents = this;
}
public void Dispose()
{
_collection._deferredEvents = null;
foreach (var args in this)
_collection.OnCollectionChanged(args);
}
}
#endregion Private Types
}
/// <remarks>
/// To be kept outside <see cref="ObservableCollection{T}"/>, since otherwise, a new instance will be created for each generic type used.
/// </remarks>
internal static class EventArgsCache
{
internal static readonly PropertyChangedEventArgs CountPropertyChanged = new PropertyChangedEventArgs("Count");
internal static readonly PropertyChangedEventArgs IndexerPropertyChanged = new PropertyChangedEventArgs("Item[]");
internal static readonly NotifyCollectionChangedEventArgs ResetCollectionChanged = new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset);
}
}আমি মনে করি অ্যাডরেঞ্জ এর মতো আরও ভালভাবে প্রয়োগ করা হয়েছে:
public void AddRange(IEnumerable<T> collection)
{
foreach (var i in collection) Items.Add(i);
OnCollectionChanged(
new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}এটি আপনার তালিকার অনুলিপি সংরক্ষণ করে। এছাড়াও আপনি যদি মাইক্রো-অপ্টিমাইজ করতে চান তবে আপনি এন আইটেম যুক্ত করতে পারেন এবং এন-এর চেয়ে বেশি আইটেম যুক্ত হলে পুনরায় সেট করতে পারেন।
আপনার কাস্টম সংগ্রহের সাথে ইউআইকে আবদ্ধ করার বিষয়ে আপনাকে সতর্কতা অবলম্বন করতে হবে - ডিফল্ট কালেকশনভিউ ক্লাস কেবলমাত্র আইটেমগুলির একক বিজ্ঞপ্তি সমর্থন করে।
প্রয়োজনীয়তার প্রমাণ OnPropertyChanged("Count")এবং OnPropertyChanged("Item[]")কল হিসাবে কল করার জন্য কল ObservableCollection। মনে রাখবেন যে আপনি বিরক্ত না করলে পরিণতিগুলি কী তা আমি জানি না!
এখানে একটি পরীক্ষা পদ্ধতি যা দেখায় যে একটি সাধারণ পর্যবেক্ষণযোগ্য সংগ্রহে প্রতিটি অ্যাডের জন্য দুটি প্রপার্টি চেঞ্জ ইভেন্ট রয়েছে। "Count"একটির জন্য এবং একটির জন্য "Item[]"।
[TestMethod]
public void TestAddSinglesInOldObsevableCollection()
{
int colChangedEvents = 0;
int propChangedEvents = 0;
var collection = new ObservableCollection<object>();
collection.CollectionChanged += (sender, e) => { colChangedEvents++; };
(collection as INotifyPropertyChanged).PropertyChanged += (sender, e) => { propChangedEvents++; };
collection.Add(new object());
collection.Add(new object());
collection.Add(new object());
Assert.AreEqual(3, colChangedEvents);
Assert.AreEqual(6, propChangedEvents);
}@ শিমি, আপনার সংগ্রহের মানটি অদলবদল করুন এবং একটি অ্যাড রেঞ্জে পরিবর্তন করুন এবং আপনি শূন্য প্রপার্টি চেঞ্জ পাবেন। নোট করুন যে সংগ্রহ পরিবর্তনটি ঠিক কাজ করে, তবে পর্যবেক্ষণযোগ্য সংগ্রহ কী করে তা ঠিক করে না। শিমি সংগ্রহের জন্য টেস্টটি দেখতে এরকম দেখাচ্ছে:
[TestMethod]
public void TestShimmyAddRange()
{
int colChangedEvents = 0;
int propChangedEvents = 0;
var collection = new ShimmyObservableCollection<object>();
collection.CollectionChanged += (sender, e) => { colChangedEvents++; };
(collection as INotifyPropertyChanged).PropertyChanged += (sender, e) => { propChangedEvents++; };
collection.AddRange(new[]{
new object(), new object(), new object(), new object()}); //4 objects at once
Assert.AreEqual(1, colChangedEvents); //great, just one!
Assert.AreEqual(2, propChangedEvents); //fails, no events :(
}এফওয়াইআই এখানে পর্যবেক্ষণযোগ্য সংগ্রহ থেকে ইনসার্ট আইটেম (অ্যাড নামে পরিচিত) এর কোড:
protected override void InsertItem(int index, T item)
{
base.CheckReentrancy();
base.InsertItem(index, item);
base.OnPropertyChanged("Count");
base.OnPropertyChanged("Item[]");
base.OnCollectionChanged(NotifyCollectionChangedAction.Add, item, index);
}সি # সংক্ষিপ্ত বংশধর।
আরও পঠন: http://blogs.msdn.com/b/nathannesbit/archive/2009/04/20/addrange-and-observablecollection.aspx
public sealed class ObservableCollectionEx<T> : ObservableCollection<T>
{
#region Ctor
public ObservableCollectionEx()
{
}
public ObservableCollectionEx(List<T> list) : base(list)
{
}
public ObservableCollectionEx(IEnumerable<T> collection) : base(collection)
{
}
#endregion
/// <summary>
/// Adds the elements of the specified collection to the end of the ObservableCollection(Of T).
/// </summary>
public void AddRange(
IEnumerable<T> itemsToAdd,
ECollectionChangeNotificationMode notificationMode = ECollectionChangeNotificationMode.Add)
{
if (itemsToAdd == null)
{
throw new ArgumentNullException("itemsToAdd");
}
CheckReentrancy();
if (notificationMode == ECollectionChangeNotificationMode.Reset)
{
foreach (var i in itemsToAdd)
{
Items.Add(i);
}
OnPropertyChanged(new PropertyChangedEventArgs("Count"));
OnPropertyChanged(new PropertyChangedEventArgs("Item[]"));
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
return;
}
int startIndex = Count;
var changedItems = itemsToAdd is List<T> ? (List<T>) itemsToAdd : new List<T>(itemsToAdd);
foreach (var i in changedItems)
{
Items.Add(i);
}
OnPropertyChanged(new PropertyChangedEventArgs("Count"));
OnPropertyChanged(new PropertyChangedEventArgs("Item[]"));
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, changedItems, startIndex));
}
public enum ECollectionChangeNotificationMode
{
/// <summary>
/// Notifies that only a portion of data was changed and supplies the changed items (not supported by some elements,
/// like CollectionView class).
/// </summary>
Add,
/// <summary>
/// Notifies that the entire collection was changed, does not supply the changed items (may be inneficient with large
/// collections as requires the full update even if a small portion of items was added).
/// </summary>
Reset
}
}হ্যাঁ, আপনার নিজস্ব কাস্টম পর্যবেক্ষণযোগ্য সংগ্রহ যোগ করা যথেষ্ট ন্যায্য হবে। মুহুর্তের জন্য এটি ইউআই ব্যবহার করছে কিনা তা বিবেচনা না করে যথাযথ ইভেন্টগুলি তুলতে ভুলবেন না;) আপনাকে "আইটেম []" সম্পত্তি (ডাব্লুপিএফ পাশ এবং আবদ্ধ নিয়ন্ত্রণের জন্য প্রয়োজনীয়) এর জন্য সম্পত্তি পরিবর্তন নোটিফিকেশন এবং নোটিফিকেশন কালজেনড অ্যাভেন্টআর্গস উত্থাপন করতে হবে সংযুক্ত আইটেমগুলির সেট সহ (আপনার পরিসর)। আমি এই জাতীয় জিনিসগুলি করেছি (পাশাপাশি সমর্থন এবং কিছু অন্যান্য জিনিস বাছাই করার জন্য) এবং উপস্থাপনা এবং স্তর উভয় স্তরগুলির সাথে কোনও সমস্যা ছিল না।
যেহেতু একটি পর্যবেক্ষণযোগ্য সংগ্রহের জন্য বেশ কয়েকটি অপারেশন থাকতে পারে উদাহরণস্বরূপ প্রথমে অ্যাড্রেঞ্জ সাফ করুন এবং তারপরে কম্বোবক্সের জন্য "সমস্ত" আইটেমটি সন্নিবেশ করান আমি শেষের সমাধানের সাথে শেষ করেছি:
public static class LinqExtensions
{
public static ICollection<T> AddRange<T>(this ICollection<T> source, IEnumerable<T> addSource)
{
foreach(T item in addSource)
{
source.Add(item);
}
return source;
}
}
public class ExtendedObservableCollection<T>: ObservableCollection<T>
{
public void Execute(Action<IList<T>> itemsAction)
{
itemsAction(Items);
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
}এবং এটি কীভাবে ব্যবহার করবেন তা উদাহরণস্বরূপ:
MyDogs.Execute(items =>
{
items.Clear();
items.AddRange(Context.Dogs);
items.Insert(0, new Dog { Id = 0, Name = "All Dogs" });
});কার্যনির্বাহী অন্তর্ভুক্ত তালিকাটি প্রক্রিয়া শেষ করার পরে পুনরায় সেট করুন বিজ্ঞপ্তি কল করা হবে called
সংগ্রহ পরিবর্তিত এবং ইউআই বিষয়গুলির জন্য এখানে কিছু অতিরিক্ত সহায়তা দেওয়া হয়েছে:
পর্যবেক্ষণযোগ্য রেঞ্জ সংগ্রহের মতো একটি পরীক্ষায় পাস করা উচিত
[Test]
public void TestAddRangeWhileBoundToListCollectionView()
{
int collectionChangedEventsCounter = 0;
int propertyChangedEventsCounter = 0;
var collection = new ObservableRangeCollection<object>();
collection.CollectionChanged += (sender, e) => { collectionChangedEventsCounter++; };
(collection as INotifyPropertyChanged).PropertyChanged += (sender, e) => { propertyChangedEventsCounter++; };
var list = new ListCollectionView(collection);
collection.AddRange(new[] { new object(), new object(), new object(), new object() });
Assert.AreEqual(4, collection.Count);
Assert.AreEqual(1, collectionChangedEventsCounter);
Assert.AreEqual(2, propertyChangedEventsCounter);
}অন্যথায় আমরা পেতে
System.NotSupportedException : Range actions are not supported.একটি নিয়ন্ত্রণ সঙ্গে ব্যবহার করার সময়।
আমি একটি আদর্শ সমাধান দেখতে পাচ্ছি না, তবে আংশিকভাবে সমস্যার সমাধান করুন / সরান পরিবর্তে পুনরায় সেট করুন Col নেট_প্রগ দ্বারা উল্লিখিত হিসাবে http://blogs.msdn.com/b/nathannesbit/archive/2009/04/20/addrange-and-observablecollection.aspx দেখুন
আরও কার্যকারিতা সরবরাহ করার জন্য গৃহীত উত্তরের একটি পরিবর্তন এখানে।
RangeCollection.cs:
public class RangeCollection<T> : ObservableCollection<T>
{
#region Members
/// <summary>
/// Occurs when a single item is added.
/// </summary>
public event EventHandler<ItemAddedEventArgs<T>> ItemAdded;
/// <summary>
/// Occurs when a single item is inserted.
/// </summary>
public event EventHandler<ItemInsertedEventArgs<T>> ItemInserted;
/// <summary>
/// Occurs when a single item is removed.
/// </summary>
public event EventHandler<ItemRemovedEventArgs<T>> ItemRemoved;
/// <summary>
/// Occurs when a single item is replaced.
/// </summary>
public event EventHandler<ItemReplacedEventArgs<T>> ItemReplaced;
/// <summary>
/// Occurs when items are added to this.
/// </summary>
public event EventHandler<ItemsAddedEventArgs<T>> ItemsAdded;
/// <summary>
/// Occurs when items are removed from this.
/// </summary>
public event EventHandler<ItemsRemovedEventArgs<T>> ItemsRemoved;
/// <summary>
/// Occurs when items are replaced within this.
/// </summary>
public event EventHandler<ItemsReplacedEventArgs<T>> ItemsReplaced;
/// <summary>
/// Occurs when entire collection is cleared.
/// </summary>
public event EventHandler<ItemsClearedEventArgs<T>> ItemsCleared;
/// <summary>
/// Occurs when entire collection is replaced.
/// </summary>
public event EventHandler<CollectionReplacedEventArgs<T>> CollectionReplaced;
#endregion
#region Helper Methods
/// <summary>
/// Throws exception if any of the specified objects are null.
/// </summary>
private void Check(params T[] Items)
{
foreach (T Item in Items)
{
if (Item == null)
{
throw new ArgumentNullException("Item cannot be null.");
}
}
}
private void Check(IEnumerable<T> Items)
{
if (Items == null) throw new ArgumentNullException("Items cannot be null.");
}
private void Check(IEnumerable<IEnumerable<T>> Items)
{
if (Items == null) throw new ArgumentNullException("Items cannot be null.");
}
private void RaiseChanged(NotifyCollectionChangedAction Action)
{
this.OnPropertyChanged(new PropertyChangedEventArgs("Count"));
this.OnPropertyChanged(new PropertyChangedEventArgs("Item[]"));
this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
#endregion
#region Bulk Methods
/// <summary>
/// Adds the elements of the specified collection to the end of this.
/// </summary>
public void AddRange(IEnumerable<T> NewItems)
{
this.Check(NewItems);
foreach (var i in NewItems) this.Items.Add(i);
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
this.OnItemsAdded(new ItemsAddedEventArgs<T>(NewItems));
}
/// <summary>
/// Adds variable IEnumerable<T> to this.
/// </summary>
/// <param name="List"></param>
public void AddRange(params IEnumerable<T>[] NewItems)
{
this.Check(NewItems);
foreach (IEnumerable<T> Items in NewItems) foreach (T Item in Items) this.Items.Add(Item);
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
//TO-DO: Raise OnItemsAdded with combined IEnumerable<T>.
}
/// <summary>
/// Removes the first occurence of each item in the specified collection.
/// </summary>
public void Remove(IEnumerable<T> OldItems)
{
this.Check(OldItems);
foreach (var i in OldItems) Items.Remove(i);
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
OnItemsRemoved(new ItemsRemovedEventArgs<T>(OldItems));
}
/// <summary>
/// Removes all occurences of each item in the specified collection.
/// </summary>
/// <param name="itemsToRemove"></param>
public void RemoveAll(IEnumerable<T> OldItems)
{
this.Check(OldItems);
var set = new HashSet<T>(OldItems);
var list = this as List<T>;
int i = 0;
while (i < this.Count) if (set.Contains(this[i])) this.RemoveAt(i); else i++;
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
OnItemsRemoved(new ItemsRemovedEventArgs<T>(OldItems));
}
/// <summary>
/// Replaces all occurences of a single item with specified item.
/// </summary>
public void ReplaceAll(T Old, T New)
{
this.Check(Old, New);
this.Replace(Old, New, false);
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
this.OnItemReplaced(new ItemReplacedEventArgs<T>(Old, New));
}
/// <summary>
/// Clears this and adds specified collection.
/// </summary>
public void ReplaceCollection(IEnumerable<T> NewItems, bool SupressEvent = false)
{
this.Check(NewItems);
IEnumerable<T> OldItems = new List<T>(this.Items);
this.Items.Clear();
foreach (T Item in NewItems) this.Items.Add(Item);
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
this.OnReplaced(new CollectionReplacedEventArgs<T>(OldItems, NewItems));
}
private void Replace(T Old, T New, bool BreakFirst)
{
List<T> Cloned = new List<T>(this.Items);
int i = 0;
foreach (T Item in Cloned)
{
if (Item.Equals(Old))
{
this.Items.Remove(Item);
this.Items.Insert(i, New);
if (BreakFirst) break;
}
i++;
}
}
/// <summary>
/// Replaces the first occurence of a single item with specified item.
/// </summary>
public void Replace(T Old, T New)
{
this.Check(Old, New);
this.Replace(Old, New, true);
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
this.OnItemReplaced(new ItemReplacedEventArgs<T>(Old, New));
}
#endregion
#region New Methods
/// <summary>
/// Removes a single item.
/// </summary>
/// <param name="Item"></param>
public new void Remove(T Item)
{
this.Check(Item);
base.Remove(Item);
OnItemRemoved(new ItemRemovedEventArgs<T>(Item));
}
/// <summary>
/// Removes a single item at specified index.
/// </summary>
/// <param name="i"></param>
public new void RemoveAt(int i)
{
T OldItem = this.Items[i]; //This will throw first if null
base.RemoveAt(i);
OnItemRemoved(new ItemRemovedEventArgs<T>(OldItem));
}
/// <summary>
/// Clears this.
/// </summary>
public new void Clear()
{
IEnumerable<T> OldItems = new List<T>(this.Items);
this.Items.Clear();
this.RaiseChanged(NotifyCollectionChangedAction.Reset);
this.OnCleared(new ItemsClearedEventArgs<T>(OldItems));
}
/// <summary>
/// Adds a single item to end of this.
/// </summary>
/// <param name="t"></param>
public new void Add(T Item)
{
this.Check(Item);
base.Add(Item);
this.OnItemAdded(new ItemAddedEventArgs<T>(Item));
}
/// <summary>
/// Inserts a single item at specified index.
/// </summary>
/// <param name="i"></param>
/// <param name="t"></param>
public new void Insert(int i, T Item)
{
this.Check(Item);
base.Insert(i, Item);
this.OnItemInserted(new ItemInsertedEventArgs<T>(Item, i));
}
/// <summary>
/// Returns list of T.ToString().
/// </summary>
/// <returns></returns>
public new IEnumerable<string> ToString()
{
foreach (T Item in this) yield return Item.ToString();
}
#endregion
#region Event Methods
private void OnItemAdded(ItemAddedEventArgs<T> i)
{
if (this.ItemAdded != null) this.ItemAdded(this, new ItemAddedEventArgs<T>(i.NewItem));
}
private void OnItemInserted(ItemInsertedEventArgs<T> i)
{
if (this.ItemInserted != null) this.ItemInserted(this, new ItemInsertedEventArgs<T>(i.NewItem, i.Index));
}
private void OnItemRemoved(ItemRemovedEventArgs<T> i)
{
if (this.ItemRemoved != null) this.ItemRemoved(this, new ItemRemovedEventArgs<T>(i.OldItem));
}
private void OnItemReplaced(ItemReplacedEventArgs<T> i)
{
if (this.ItemReplaced != null) this.ItemReplaced(this, new ItemReplacedEventArgs<T>(i.OldItem, i.NewItem));
}
private void OnItemsAdded(ItemsAddedEventArgs<T> i)
{
if (this.ItemsAdded != null) this.ItemsAdded(this, new ItemsAddedEventArgs<T>(i.NewItems));
}
private void OnItemsRemoved(ItemsRemovedEventArgs<T> i)
{
if (this.ItemsRemoved != null) this.ItemsRemoved(this, new ItemsRemovedEventArgs<T>(i.OldItems));
}
private void OnItemsReplaced(ItemsReplacedEventArgs<T> i)
{
if (this.ItemsReplaced != null) this.ItemsReplaced(this, new ItemsReplacedEventArgs<T>(i.OldItems, i.NewItems));
}
private void OnCleared(ItemsClearedEventArgs<T> i)
{
if (this.ItemsCleared != null) this.ItemsCleared(this, new ItemsClearedEventArgs<T>(i.OldItems));
}
private void OnReplaced(CollectionReplacedEventArgs<T> i)
{
if (this.CollectionReplaced != null) this.CollectionReplaced(this, new CollectionReplacedEventArgs<T>(i.OldItems, i.NewItems));
}
#endregion
#region RangeCollection
/// <summary>
/// Initializes a new instance.
/// </summary>
public RangeCollection() : base() { }
/// <summary>
/// Initializes a new instance from specified enumerable.
/// </summary>
public RangeCollection(IEnumerable<T> Collection) : base(Collection) { }
/// <summary>
/// Initializes a new instance from specified list.
/// </summary>
public RangeCollection(List<T> List) : base(List) { }
/// <summary>
/// Initializes a new instance with variable T.
/// </summary>
public RangeCollection(params T[] Items) : base()
{
this.AddRange(Items);
}
/// <summary>
/// Initializes a new instance with variable enumerable.
/// </summary>
public RangeCollection(params IEnumerable<T>[] Items) : base()
{
this.AddRange(Items);
}
#endregion
}ইভেন্ট ক্লাস:
public class CollectionReplacedEventArgs<T> : ReplacedEventArgs<T>
{
public CollectionReplacedEventArgs(IEnumerable<T> Old, IEnumerable<T> New) : base(Old, New) { }
}
public class ItemAddedEventArgs<T> : EventArgs
{
public T NewItem;
public ItemAddedEventArgs(T t)
{
this.NewItem = t;
}
}
public class ItemInsertedEventArgs<T> : EventArgs
{
public int Index;
public T NewItem;
public ItemInsertedEventArgs(T t, int i)
{
this.NewItem = t;
this.Index = i;
}
}
public class ItemRemovedEventArgs<T> : EventArgs
{
public T OldItem;
public ItemRemovedEventArgs(T t)
{
this.OldItem = t;
}
}
public class ItemReplacedEventArgs<T> : EventArgs
{
public T OldItem;
public T NewItem;
public ItemReplacedEventArgs(T Old, T New)
{
this.OldItem = Old;
this.NewItem = New;
}
}
public class ItemsAddedEventArgs<T> : EventArgs
{
public IEnumerable<T> NewItems;
public ItemsAddedEventArgs(IEnumerable<T> t)
{
this.NewItems = t;
}
}
public class ItemsClearedEventArgs<T> : RemovedEventArgs<T>
{
public ItemsClearedEventArgs(IEnumerable<T> Old) : base(Old) { }
}
public class ItemsRemovedEventArgs<T> : RemovedEventArgs<T>
{
public ItemsRemovedEventArgs(IEnumerable<T> Old) : base(Old) { }
}
public class ItemsReplacedEventArgs<T> : ReplacedEventArgs<T>
{
public ItemsReplacedEventArgs(IEnumerable<T> Old, IEnumerable<T> New) : base(Old, New) { }
}
public class RemovedEventArgs<T> : EventArgs
{
public IEnumerable<T> OldItems;
public RemovedEventArgs(IEnumerable<T> Old)
{
this.OldItems = Old;
}
}
public class ReplacedEventArgs<T> : EventArgs
{
public IEnumerable<T> OldItems;
public IEnumerable<T> NewItems;
public ReplacedEventArgs(IEnumerable<T> Old, IEnumerable<T> New)
{
this.OldItems = Old;
this.NewItems = New;
}
}দ্রষ্টব্য: আমি OnCollectionChangedবেস পদ্ধতিগুলিতে ম্যানুয়ালি উত্থাপন করি নি কারণ ক্রিয়াটি CollectionChangedEventArgsব্যবহার করে এটি তৈরি করা সম্ভব বলে মনে হয় Reset। আপনি যদি কোনও একক আইটেম পরিবর্তনের জন্য OnCollectionChangedব্যবহার করে উত্থাপন করার চেষ্টা করেন Reset, আপনার আইটেম নিয়ন্ত্রণটি ঝাঁকুনির জন্য উপস্থিত হবে, যা এমন কিছু যা আপনি এড়াতে চান।
আপনি পর্যবেক্ষণযোগ্য সংগ্রহ বাড়ানোর জন্য এই কোডটি ব্যবহার করতে পারেন:
public static class ObservableCollectionExtend
{
public static void AddRange<TSource>(this ObservableCollection<TSource> source, IEnumerable<TSource> items)
{
foreach (var item in items)
{
source.Add(item);
}
}
}তারপরে আপনার বিদ্যমান কোডে ক্লাস পরিবর্তন করার দরকার নেই।