Documentation

Class VirtualQueryableCollectionView

Represents a view for grouping, sorting, filtering and paging data collection virtually.

Inheritance
System.Object
QueryableCollectionView
VirtualQueryableCollectionView
VirtualQueryableCollectionView<T>
Inherited Members
Namespace: Telerik.Windows.Data
Assembly: Telerik.Windows.Data.dll

Syntax

public class VirtualQueryableCollectionView : QueryableCollectionView, IEditableCollectionView, IEditableCollectionViewAddNewItem, ICollectionView, INotifyCollectionChanged, INotifyPropertyChanged, IPagedCollectionView, IWeakEventListener<NotifyCollectionChangedEventArgs>, IWeakEventListener<CurrentChangingEventArgs>, IQueryableCollectionView, IItemProperties, IDisposable, IList, ICollection, IEnumerable

Constructors

VirtualQueryableCollectionView()

Initializes a new instance of the VirtualQueryableCollectionView class.

Declaration
public VirtualQueryableCollectionView()

VirtualQueryableCollectionView(IEnumerable)

Initializes a new instance of the VirtualQueryableCollectionView class.

Declaration
public VirtualQueryableCollectionView(IEnumerable source)
Parameters
System.Collections.IEnumerable source

The source collection.

VirtualQueryableCollectionView(IEnumerable, Type)

Initializes a new instance of the VirtualQueryableCollectionView class.

Declaration
public VirtualQueryableCollectionView(IEnumerable source, Type itemType)
Parameters
System.Collections.IEnumerable source

System.Type itemType

Properties

CanAddNew

Gets a value that indicates whether a new item can be added to the collection.

Declaration
public override bool CanAddNew { get; }
Property Value
System.Boolean

true if SourceCollection is not System.Collections.IList.IsFixedSize or Add method is available and collection element has a default constructor; otherwise, false.
Overrides

CanRemove

Gets a value that indicates whether an item can be removed from the collection.

Declaration
public override bool CanRemove { get; }
Property Value
System.Boolean

true if an item can be removed from the collection; otherwise, false.
Overrides

InternalCount

Protected accessor to private count.

Declaration
protected override int InternalCount { get; }
Property Value
System.Int32

Overrides

InternalList

Gets the list created from resulting query after applying filtering, sorting, grouping and paging.

Declaration
protected override IList InternalList { get; }
Property Value
System.Collections.IList

The internal list for the current view.
Overrides

IsFixedSize

Declaration
public bool IsFixedSize { get; }
Property Value
System.Boolean

IsReadOnly

Declaration
public bool IsReadOnly { get; }
Property Value
System.Boolean

IsRequestingItems

Gets a value that indicates whether this view is loading items.

Declaration
public virtual bool IsRequestingItems { get; protected set; }
Property Value
System.Boolean

IsSynchronized

Declaration
public bool IsSynchronized { get; }
Property Value
System.Boolean

ItemCount

Gets the minimum number of items known to be in the source collection.

Declaration
public override int ItemCount { get; }
Property Value
System.Int32

The minimum number of items known to be in the source collection.
Overrides

LoadSize

Gets or sets the total number of items to retrieve.

Declaration
public int LoadSize { get; set; }
Property Value
System.Int32

The total number of items to retrieve.

QueryableSourceCollection

Returns the queryable collection, constructed from SourceCollection.

Declaration
public override IQueryable QueryableSourceCollection { get; }
Property Value
System.Linq.IQueryable

An System.Linq.IQueryable object that is constructed from the underlying collection.
Overrides

ShouldEnumeratorLoadItems

Gets or sets a value that indicates whether items that are not loaded yet should get loaded while the collection's enumerator is traversed.

Declaration
public bool ShouldEnumeratorLoadItems { get; set; }
Property Value
System.Boolean

SyncRoot

Declaration
public object SyncRoot { get; }
Property Value
System.Object

VirtualItemCount

Gets or sets the total number of all items.

Declaration
public int VirtualItemCount { get; set; }
Property Value
System.Int32

The total number of all items.

Methods

Add(Object)

Declaration
public int Add(object value)
Parameters
System.Object value

Returns
System.Int32

AddNew()

Adds a new item to the collection.

Declaration
public override object AddNew()
Returns
System.Object

The new item that is added to the collection.
Overrides
Exceptions
System.InvalidOperationException

CanAddNew is false.

CancelNew()

Ends the add transaction and discards the pending new item.

Declaration
public override void CancelNew()
Overrides

Clear()

Declaration
public void Clear()

CopyTo(Array, Int32)

Declaration
public void CopyTo(Array array, int index)
Parameters
System.Array array

System.Int32 index

CreateView()

Returns System.Linq.IQueryable with applied filtering, sorting, grouping and paging.

Declaration
protected override IQueryable CreateView()
Returns
System.Linq.IQueryable

Overrides

GetEnumerator()

Declaration
public override IEnumerator GetEnumerator()
Returns
System.Collections.IEnumerator

Overrides

GetItemAt(Int32)

Retrieves the item at the specified zero-based index in the view.

Declaration
public override object GetItemAt(int index)
Parameters
System.Int32 index

The zero-based index of the item to retrieve.
Returns
System.Object

The item at the specified zero-based index in the view.
Overrides
Remarks

If the item at this index is not loaded will raise ItemsLoading event. The returned item will be null or temporary dynamic item until the real item is loaded.

Exceptions
System.ArgumentOutOfRangeException

index is less than 0 or greater than ItemCount.

IndexOf(Object)

Returns the zero-based index at which the specified item is located.

Declaration
public override int IndexOf(object item)
Parameters
System.Object item

The item to locate.
Returns
System.Int32

The index at which the specified item is located, or –1 if the item is unknown.
Overrides

Insert(Int32, Object)

Declaration
public void Insert(int index, object value)
Parameters
System.Int32 index

System.Object value

InvalidatePagingAndRefresh()

Invalidates the paging and refreshes the view.

Declaration
protected override void InvalidatePagingAndRefresh()
Overrides

Load(Int32, IEnumerable)

Loads new data in the view.

Declaration
public void Load(int startIndex, IEnumerable items)
Parameters
System.Int32 startIndex

System.Collections.IEnumerable items

OnCollectionChanged(NotifyCollectionChangedEventArgs)

Raises the CollectionChanged event.

Declaration
protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs args)
Parameters
System.Collections.Specialized.NotifyCollectionChangedEventArgs args

The System.Collections.Specialized.NotifyCollectionChangedEventArgs instance containing the event data.
Overrides

OnRefresh()

Invoked when the instance should be refreshed.

Declaration
protected override void OnRefresh()
Overrides

Remove(Object)

Removes the specified item from the collection.

Declaration
public override void Remove(object item)
Parameters
System.Object item

The item to remove.
Overrides

RemoveAt(Int32)

Removes the item at the specified position from the collection.

Declaration
public override void RemoveAt(int index)
Parameters
System.Int32 index

The position of the item to remove.
Overrides

ResetItems()

Reset all items to default value (null) in the collection.

Declaration
public void ResetItems()

ResetItems(Int32, Int32)

Reset number of items starting from given index to default value (null) in the collection.

Declaration
public void ResetItems(int startIndex, int count)
Parameters
System.Int32 startIndex

System.Int32 count

Events

ItemsLoaded

Occurs when the items are loaded.

Declaration
public event EventHandler<VirtualQueryableCollectionViewItemsLoadedEventArgs> ItemsLoaded
Event Type
System.EventHandler<VirtualQueryableCollectionViewItemsLoadedEventArgs>

ItemsLoading

Occurs when the collection is about to load items.

Declaration
public event EventHandler<VirtualQueryableCollectionViewItemsLoadingEventArgs> ItemsLoading
Event Type
System.EventHandler<VirtualQueryableCollectionViewItemsLoadingEventArgs>

Extension Methods