ObservableCollection لا يدعم AddRange طريقة لذلك أنا الحصول على إخطار لكل عنصر إضافة ، إلى جانب ما عن INotifyCollectionChanging?
https://stackoverflow.com/questions/670577
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21-08-2019 - |
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أريد أن أكون قادرا على إضافة مجموعة والحصول على تحديث كامل الأكبر.
أريد أيضا أن تكون قادرة على إلغاء العمل قبل القيام به (أيجمع المتغيرة بالإضافة إلى 'تغيير').
ذات الصلة Q التي .صافي جمع لإضافة كائنات متعددة في وقت واحد والحصول على إعلامك ؟
المحلول 2
أولا وقبل كل شيء ، من فضلك التصويت والتعليق على طلب API على .صافي الريبو.
هنا هو نسخة محسنة من ObservableRangeCollection (نسخة محسنة من جيمس Montemagno هو واحد).
ينفذ سريع جدا و يهدف إلى إعادة استخدام العناصر الموجودة عند الإمكان وتجنب الأحداث أو الخلط بينهما في أحد ، عندما يكون ذلك ممكنا.على ReplaceRange طريقة يستبدل/إزالة/إضافة العناصر المطلوبة من خلال المؤشرات المناسبة و دفعات على الأحداث المحتملة.
اختبار على Xamarin.أشكال واجهة المستخدم مع نتائج عظيمة جدا تحديثات متكررة إلى مجموعة كبيرة (5-7 تحديثات في الثانية).
ملاحظة:منذ WPF ليست معتادة على العمل مع مجموعة العمليات ، فإنه سيتم رمي NotSupportedException, عند استخدام ObservableRangeCollection من أدناه في WPF UI-العمل ذات الصلة ، مثل الربط إلى ListBox الخ.(يمكنك الاستمرار في استخدام ObservableRangeCollection<T> إذا لا بد أن واجهة المستخدم).
ومع ذلك يمكنك استخدام WpfObservableRangeCollection<T> الحل البديل.
الحل الحقيقي لن يكون خلق CollectionView أن يعرف كيف يتعامل مع مجموعة العمليات ، ولكن ما زلت لم يكن لديك الوقت لتنفيذ هذا.
الخام رمز - فتح الخام ، ثم القيام Ctrl+A إلى تحديد الكل ثم Ctrl+ج نسخ.
// 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);
}
}
نصائح أخرى
يرجى الرجوع إلى تحديث وتحسين C# 7 الإصدار.لم أكن أريد أن إزالة VB.NET الإصدار لذا نشره في إجابة منفصلة.
انتقل إلى تحديث الإصدار
يبدو انها غير معتمدة ، وأنا نفذت من قبل نفسي, لمعلوماتك, نأمل أن تكون مفيدة:
لقد قمت بتحديث نسخة VB و من الآن فصاعدا فإنه يرفع الحدث قبل تغيير جمع حتى تتمكن من الأسف (مفيدة عندما تستخدم مع DataGrid, ListView والعديد من أكثر من ذلك ، يمكنك إظهار "هل أنت متأكد" تأكيد المستخدم) ، تحديث نسخة VB هو في الجزء السفلي من هذه الرسالة.
أرجو أن تقبل إعتذاري أن الشاشة هي أضيق من أن تحتوي على رمز بلادي, أنا لا أحب ذلك أيضا.
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) { }
}
تحديث - يمكن ملاحظتها مجموعة مجموعة مجموعة إعلام تغيير
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
وأعتقد AddRange هو تنفيذ أفضل مثل ذلك:
public void AddRange(IEnumerable<T> collection)
{
foreach (var i in collection) Items.Add(i);
OnCollectionChanged(
new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
وأنه يوفر لك نسخة القائمة. أيضا إذا كنت ترغب في-الأمثل الصغيرة يمكن أن تفعله يضيف لمدة تصل إلى N البنود وإذا كان أكثر من البنود N حيث أضاف القيام إعادة تعيين.
وسيكون لديك لتوخي الحذر ملزمة واجهة المستخدم لجمع المخصصة - الطبقة افتراضي CollectionView يعتمد فقط إشعار واحد من العناصر
وإثبات الحاجة إلى OnPropertyChanged("Count") وOnPropertyChanged("Item[]") يدعو لتتصرف وفقا ObservableCollection. علما بأنني لا أعرف ما هي العواقب إذا كنت لا تهتم!
وهنا هو طريقة الاختبار تبين أن هناك حدثين PropertyChange عن كل إضافة في مجموعة ملاحظتها العادي. واحد ل"Count" واحد ل"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);
}
وShimmy، مبادلة القياسية لجمع الخاصة بك وتغيير إلى مجموعة إضافية، وسوف تحصل الصفر PropertyChanges. لاحظ أن تغير جمع لا تعمل بشكل جيد، ولكن لا تفعل بالضبط ما تفعله ObservableCollection. لذلك اختبار لجمع تهتز يبدو مثل هذا:
[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 :(
}
ومعلوماتك هنا هو رمز من InsertItem (وتسمى أيضا عن طريق إضافة) من ObservableCollection:
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);
}
ووC # تلخيص سليل.
وعن القراءة: 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
}
}
نعم، مضيفا أن الخاصة مخصص ملاحظتها أغانى أخرى تكون عادلة بما فيه الكفاية. لا تنسى أن رفع أحداث المناسبة بغض النظر ما إذا كان يتم استخدامه من قبل UI لحظة أم لا؛) سوف تضطر إلى رفع إعلام تغيير الملكية ل "البند []" ممتلكات (مطلوب إلى جنب والمربوطة الضوابط WPF)، وكذلك NotifyCollectionChangedEventArgs مع مجموعة من العناصر المضافة (النطاق الخاص بك). لقد فعل مثل هذه الأشياء (وكذلك فرز دعم وبعض الأشياء الأخرى)، وليس لديه مشاكل مع كل من العرض ومدونة خلف طبقات.
وكما قد يكون هناك عدد من العمليات للقيام على ObservableCollection على سبيل المثال واضح أولا ثم AddRange ثم قم بإدراج "الكل" البند للتحرير وسرد انتهى بي الأمر مع حل معلمات أكثر:
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));
}
}
والمثال كيفية استخدامه:
MyDogs.Execute(items =>
{
items.Clear();
items.AddRange(Context.Dogs);
items.Insert(0, new Dog { Id = 0, Name = "All Dogs" });
});
والإخطار إعادة تعيين وسوف يطلق مرة واحدة فقط بعد الانتهاء من تنفيذ معالجة القائمة الأساسية.
هنا بعض مساعدة إضافية لجمع تغيرت واجهة المستخدم قضايا:
وObservableRangeCollection يجب اجتياز اختبار مثل
[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);
}
وإلا فإننا حصول
System.NotSupportedException : Range actions are not supported.
وأثناء استخدام مع جهاز تحكم.
وأنا لا أرى حلا مثاليا، ولكن NotifyCollectionChangedAction.Reset بدلا من إضافة / إزالة جزئيا في حل المشكلة. انظر HTTP: //blogs.msdn. كوم / ب / nathannesbit / أرشيف / 2009/04/20 / addrange و-observablecollection.aspx كما ذكره net_prog
وهنا تعديل للإجابة مقبولة لتوفير المزيد من الوظائف.
وRangeCollection.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
}
والفعاليات فصول:
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;
}
}
ملحوظة: لم أكن رفع OnCollectionChanged يدويا في أساليب القاعدة لأنه يبدو فقط ليكون من الممكن لخلق CollectionChangedEventArgs باستخدام إجراء Reset. إذا حاولت رفع OnCollectionChanged باستخدام Reset لتغيير عنصر واحد، السيطرة ستظهر البنود الخاصة بك للتومض، وهو ما كنت ترغب في تجنب.
ويمكنك أيضا استخدام هذا الرمز لتمديد ObservableCollection:
public static class ObservableCollectionExtend
{
public static void AddRange<TSource>(this ObservableCollection<TSource> source, IEnumerable<TSource> items)
{
foreach (var item in items)
{
source.Add(item);
}
}
}
وبعد ذلك لا تحتاج إلى تغيير الطبقة في التعليمات البرمجية الموجودة.
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