Class PagedCollectionView

Represents the class that maintains the collection view of type paged collection view, when the SfDataGrid is bind to the paged collection view.

Inheritance
System.Object
CollectionViewAdv
QueryableCollectionView
PagedCollectionView
Implements
Microsoft.UI.Xaml.Data.ICollectionView
Windows.Foundation.Collections.IObservableVector<System.Object>
System.Collections.Generic.IList<System.Object>
System.Collections.Generic.ICollection<System.Object>
System.Collections.Generic.IEnumerable<System.Object>
System.Collections.IEnumerable
System.ComponentModel.INotifyPropertyChanged
System.IDisposable
Inherited Members
Namespace: Syncfusion.UI.Xaml.Data
Assembly: Syncfusion.Data.WinUI.dll
Syntax
public class PagedCollectionView : QueryableCollectionView, ICollectionViewAdv, ICollectionView, IObservableVector<object>, IList<object>, ICollection<object>, IEnumerable<object>, IEnumerable, INotifyPropertyChanged, ISupportInitialize, IDisposable, IEditableCollectionView, IUnboundExpressionFunc, IGridViewNotifier, IFilterPredicateExpression, IParallelizableView, IPagedCollectionView

Constructors

PagedCollectionView()

Initializes a new instance of the PagedCollectionView class.

Declaration
public PagedCollectionView()

PagedCollectionView(IEnumerable)

Initializes a new instance of the PagedCollectionView class.

Declaration
public PagedCollectionView(IEnumerable source)
Parameters
Type Name Description
System.Collections.IEnumerable source

The IEnumerable source of the SfDataGrid.

Fields

OnDemandPageCache

Gets the on demand paged cache which contains the cache of the records in the previous page.

Declaration
protected Dictionary<int, IEnumerable> OnDemandPageCache
Field Value
Type
System.Collections.Generic.Dictionary<System.Int32, System.Collections.IEnumerable>

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
Type Description
System.Boolean

True if a new item can be added to the collection, otherwisefalse.
Overrides

EnableSummaryOptimization

Gets or sets a boolean value that indicates whether to enable optimistic summary calculation on real time updates.

Declaration
public override bool EnableSummaryOptimization { get; }
Property Value
Type Description
System.Boolean

A boolean value that indicates whether to enable optimistic summary calculation on real time updates.
Overrides
Remarks

The EnableSummaryOptimization calculates the summary optimistically when the data objects implement the System.ComponentModel.INotifyPropertyChanging and System.ComponentModel.INotifyPropertyChanged.

FilterPredicates

Gets or sets the collection of FilterPredicates, based on which filtering is performed in the underlying collection.

Declaration
public override ObservableCollection<IFilterDefinition> FilterPredicates { get; set; }
Property Value
Type Description
System.Collections.ObjectModel.ObservableCollection<IFilterDefinition>

The collection of FilterPredicates, based on which filtering is performed in the underlying collection.
Overrides

ItemCount

Gets the number of items in the collection view.

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

The number of items in the collection view.

MaxItemsCount

Gets or sets the maximum items count in the paged collection view.

Declaration
public int MaxItemsCount { get; set; }
Property Value
Type Description
System.Int32

The maximum items count in the paged collection view.

PageCount

Gets the number of pages in the paged collection view.

Declaration
public virtual int PageCount { get; }
Property Value
Type Description
System.Int32

The number of pages in the paged collection view.

PageIndex

Gets the page index of the current page.

Declaration
public int PageIndex { get; }
Property Value
Type Description
System.Int32

The page index of the current page.

PageSize

Gets or sets the page size, which indicates the number of rows to be displayed in the page.

Declaration
public int PageSize { get; set; }
Property Value
Type Description
System.Int32

The page size, which indicates the number of rows to be displayed in the page.

TotalItemCount

Gets the total items count in the collection view.

Declaration
public int TotalItemCount { get; }
Property Value
Type Description
System.Int32

The total items count in the collection view.

UseOnDemandPaging

Gets or sets a boolean value indicating whether to use on demand paging, when on demand paging is enabled the items will be populated to the page only when navigated to the page.

Declaration
public bool UseOnDemandPaging { get; set; }
Property Value
Type Description
System.Boolean

A boolean value indicating whether to use on demand paging.

Methods

add_OnDemandItemsLoading(OnDemandItemsLoadingEventHandler)

Declaration
public void add_OnDemandItemsLoading(OnDemandItemsLoadingEventHandler value)
Parameters
Type Name Description
OnDemandItemsLoadingEventHandler value

AdjustBeforeAdd(Object, Int32)

Adjust the underlying collection by getting the comparer index before adding the given record at the given index in the view.

Declaration
protected override int AdjustBeforeAdd(object record, int index)
Parameters
Type Name Description
System.Object record

The record to be added to the collection.
System.Int32 index

The index at which the record is to be added.
Returns
Type Description
System.Int32

Gets the comparer index based on the given index and records in the collection.
Overrides

CommitEdit()

Ends the edit transaction and saves the pending changes.

Declaration
public override void CommitEdit()
Overrides

CreateRecords()

Creates the records for the items in the source of the collection view.

Declaration
protected override RecordsList CreateRecords()
Returns
Type Description
RecordsList

The list of records created for the items in the source of the collection view.
Overrides

EnsureView()

Ensures sorting, grouping and filtering by refreshing the view with updated collection.

Declaration
protected override void EnsureView()
Overrides

GetComparerIndex(Object, Int32)

Compares the given index and the index corresponding to the given record.

Call this method when you need to find the compared index of item based on sorting

Declaration
protected override int GetComparerIndex(object record, int index)
Parameters
Type Name Description
System.Object record

The record whose index is to be compared with the given index.
System.Int32 index

The index which is to be compared
Returns
Type Description
System.Int32

Gets the comparer index based on the given index and the index corresponding to the given record.
Overrides

GetGroupResult(String[])

Gets the IEnumerable collection of group result for the array of group-by.

Declaration
protected override IEnumerable<GroupResult> GetGroupResult(string[] groupBy)
Parameters
Type Name Description
System.String[] groupBy

The array of groups
Returns
Type Description
System.Collections.Generic.IEnumerable<GroupResult>

The IEnumerable collection of group result for the array of group-by.
Overrides

GetQueryableSource()

Returns the IQueryable source of the collection view.

Declaration
protected override IQueryable GetQueryableSource()
Returns
Type Description
System.Linq.IQueryable

The IQueryable source of the collection view.
Overrides
Remarks

PagedCollectionView returns paged source as IQueryable. Returning query will be sorted query in the case of normal VirtualizingCollectionView. It will be sorted and filtered query in the case of PagedCollectionVeiw and OnDemand VirtualizingCollectionView.

LoadDynamicItems(Int32, IEnumerable)

Loads the given items starting from the given page index, dynamically to the page.

Declaration
public void LoadDynamicItems(int startIndex, IEnumerable items)
Parameters
Type Name Description
System.Int32 startIndex

The start index to load the items.
System.Collections.IEnumerable items

The items to be loaded to the page.

MoveToFirstPage()

Moves to the first page.

Declaration
public bool MoveToFirstPage()
Returns
Type Description
System.Boolean

Returns a boolean value indicating whether moved to the first page or not.

MoveToLastPage()

Moves to the last page.

Declaration
public bool MoveToLastPage()
Returns
Type Description
System.Boolean

Returns a boolean value indicating whether moved to the last page or not.

MoveToNextPage()

Moves to the next page.

Declaration
public bool MoveToNextPage()
Returns
Type Description
System.Boolean

Returns a boolean value indicating whether moved to the next page or not.

MoveToPage(Int32)

Moves to the given page index.

Declaration
public virtual bool MoveToPage(int pageIndex)
Parameters
Type Name Description
System.Int32 pageIndex

The page index to move to.
Returns
Type Description
System.Boolean

Returns a boolean value indicating whether moved to the given page or not.

MoveToPreviousPage()

Moves to the previous page.

Declaration
public bool MoveToPreviousPage()
Returns
Type Description
System.Boolean

Returns a boolean value indicating whether moved to the previous page or not.

NotifyPropertyChangedHandler(Object, PropertyChangedEventArgs)

This method fires when the property is changed.

Declaration
protected override void NotifyPropertyChangedHandler(object sender, PropertyChangedEventArgs e)
Parameters
Type Name Description
System.Object sender

The sender of the event.
System.ComponentModel.PropertyChangedEventArgs e

The System.ComponentModel.PropertyChangedEventArgs that contains the event for the data.
Overrides

RefreshFilter(Boolean)

Refreshes the view when the filtering is applied through FilterRecord(Object) delegate.

Declaration
public override void RefreshFilter(bool isProgrammatic = false)
Parameters
Type Name Description
System.Boolean isProgrammatic

A boolean value indicating whether filtering is done programmatically.
Overrides

RefreshSort()

Refreshes sorting in the underlying collection of the SfDataGrid.

Declaration
protected override void RefreshSort()
Overrides

Remove(Object)

Removes the given item from the collection.

Declaration
public override bool Remove(object item)
Parameters
Type Name Description
System.Object item

The item to be removed.
Returns
Type
System.Boolean
Overrides

remove_OnDemandItemsLoading(OnDemandItemsLoadingEventHandler)

Declaration
public void remove_OnDemandItemsLoading(OnDemandItemsLoadingEventHandler value)
Parameters
Type Name Description
OnDemandItemsLoadingEventHandler value

ResetCache()

Clears the cache while using OnDemandPaging.

Declaration
public void ResetCache()
Remarks

While navigating between pages, records are loaded through OnDemandItemsLoading event and the loaded records will be maintained in cache. If you navigate to already navigated page, then records are loaded from cache and the OnDemandItemsLoading event will not fire for that corresponding page. You can clear the cache by using this method and now the OnDemandItemsLoading event will be raised when you navigate to the same page. And the records will be loaded through event instead of loading from cache.

ResetCacheForPage(Int32)

Reset the cache to the given page index.

Declaration
public void ResetCacheForPage(int pageIndex)
Parameters
Type Name Description
System.Int32 pageIndex

Index of the page to reset its cache.
See Also

SetSource(IEnumerable)

Sets the given source to the collection view.

Declaration
protected override void SetSource(IEnumerable _source)
Parameters
Type Name Description
System.Collections.IEnumerable _source

The source to be set to the collection view.
Overrides

UpdateCollectionView(Object, NotifyCollectionChangedEventArgs)

This method fires when the collection is changed.

Declaration
protected override void UpdateCollectionView(object sender, NotifyCollectionChangedEventArgs e)
Parameters
Type Name Description
System.Object sender

The original sender of the event.
System.Collections.Specialized.NotifyCollectionChangedEventArgs e

The System.Collections.Specialized.NotifyCollectionChangedAction which represents the collection changed action.
Overrides

Events

OnDemandItemsLoading

Occurs when the items are loaded on demand to the page.

Declaration
public event OnDemandItemsLoadingEventHandler OnDemandItemsLoading
Event Type
Type
OnDemandItemsLoadingEventHandler

PageChanged

Occurs when the page is changed.

Declaration
public event EventHandler<PageChangedEventArgs> PageChanged
Event Type
Type
System.EventHandler<PageChangedEventArgs>

PageChanging

Occurs when the page is changing.

Declaration
public event EventHandler<PageChangingEventArgs> PageChanging
Event Type
Type
System.EventHandler<PageChangingEventArgs>

Implements

Microsoft.UI.Xaml.Data.ICollectionView
Windows.Foundation.Collections.IObservableVector<>
System.Collections.Generic.IList<>
System.Collections.Generic.ICollection<>
System.Collections.Generic.IEnumerable<>
System.Collections.IEnumerable
System.ComponentModel.INotifyPropertyChanged
System.IDisposable

Extension Methods