Пример #1
0
        private static void OnItemsSourcePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            MyVirtualizingPanel2 virtualizingPanel2 = d as MyVirtualizingPanel2;

            if (virtualizingPanel2 == null)
            {
                return;
            }
            virtualizingPanel2.ClearItems();
            INotifyCollectionChanged collection1 = e.OldValue as INotifyCollectionChanged;

            if (collection1 != null)
            {
                virtualizingPanel2.UnhookCollectionChanged(collection1);
            }
            INotifyCollectionChanged collection2 = e.NewValue as INotifyCollectionChanged;

            if (collection2 != null)
            {
                List <IVirtualizable> virtualizableList = new List <IVirtualizable>();
                foreach (object obj in (IEnumerable)(collection2 as ICollection))
                {
                    if (obj is IVirtualizable)
                    {
                        virtualizableList.Add(obj as IVirtualizable);
                    }
                    else if (virtualizingPanel2.CreateVirtItemFunc != null)
                    {
                        virtualizableList.Add(virtualizingPanel2.CreateVirtItemFunc(obj));
                    }
                }
                virtualizingPanel2.AddItems((IEnumerable <IVirtualizable>)virtualizableList);
                virtualizingPanel2.HookUpCollectionChanged(collection2);
                virtualizingPanel2.SubscribeOnEdit();
            }
            else
            {
                virtualizingPanel2.UnsubscribeOnEdit();
            }
        }
Пример #2
0
        private void collection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            MyVirtualizingPanel2  virtualizingPanel2 = this;
            List <IVirtualizable> itemsToInsert      = new List <IVirtualizable>();

            if (e.NewItems != null)
            {
                foreach (object newItem in (IEnumerable)e.NewItems)
                {
                    if (newItem is IVirtualizable)
                    {
                        itemsToInsert.Add(newItem as IVirtualizable);
                    }
                    else if (this.CreateVirtItemFunc != null)
                    {
                        itemsToInsert.Add(this.CreateVirtItemFunc(newItem));
                    }
                }
            }
            List <IVirtualizable> virtualizableList1 = new List <IVirtualizable>();

            if (e.OldItems != null)
            {
                foreach (object oldItem in (IEnumerable)e.OldItems)
                {
                    if (oldItem is IVirtualizable)
                    {
                        virtualizableList1.Add(oldItem as IVirtualizable);
                    }
                    else if (e.OldStartingIndex >= 0 && e.OldStartingIndex < virtualizingPanel2.VirtualizableItems.Count)
                    {
                        IVirtualizable itemToBeRemoved = virtualizingPanel2.VirtualizableItems[e.OldStartingIndex];
                        virtualizingPanel2.RemoveItem(itemToBeRemoved);
                    }
                }
            }
            if (this._isEditing)
            {
                this._addedWhileEdited.AddRange((IEnumerable <IVirtualizable>)itemsToInsert);
            }
            else if (e.Action == NotifyCollectionChangedAction.Add)
            {
                if (e.NewStartingIndex >= virtualizingPanel2.VirtualizableItems.Count)
                {
                    virtualizingPanel2.AddItems((IEnumerable <IVirtualizable>)itemsToInsert);
                }
                else
                {
                    virtualizingPanel2.InsertRemoveItems(e.NewStartingIndex, itemsToInsert, virtualizingPanel2.KeepScrollPositionWhenAddingItems, (IVirtualizable)null);
                }
            }
            else if (e.Action == NotifyCollectionChangedAction.Reset)
            {
                virtualizingPanel2.ClearItems();
                List <IVirtualizable> virtualizableList2 = new List <IVirtualizable>();
                foreach (object obj in (IEnumerable)virtualizingPanel2.ItemsSource)
                {
                    virtualizableList2.Add(obj is IVirtualizable ? obj as IVirtualizable : this.CreateVirtItemFunc(obj));
                }
                virtualizingPanel2.AddItems((IEnumerable <IVirtualizable>)virtualizableList2);
            }
            else
            {
                if (e.Action != NotifyCollectionChangedAction.Remove || virtualizableList1.Count <= 0)
                {
                    return;
                }
                virtualizingPanel2.RemoveItem(virtualizableList1[0]);
            }
        }