C# Class IdeaBlade.Windows.EntityQueryPagedCollectionView

A collection providing paging, sorting, grouping and filtering of query results.

The EntityQueryPagedCollectionView can be used from code behind, and view models in MVVM architectures, to provide paged results to bound controls. It is also used internally by the ObjectDataSource when declarative specification in XAML is wanted.

The EntityQuery provided in the constructor will be executed asynchronously as needed to fulfill each paging request. Note that unless a CacheOnly query strategy is defined, the first time a page is loaded it will use a DataSourceOnly fetch strategy. Subsequent executions will use the QueryStrategy defined on the query. Note that the query must be an EntityQuery, you can't use this collection with a StoredProcQuery or PassthruEsqlQuery. For those queries, use the .NET PagedCollectionView instead.

The EntityManager of the query is used to perform query execution. If none is specified an exception is thrown. If the EntityManager is not logged in, an asynchronous login with null credentials is performed.

To use with a DataPager control, set or bind its Source property to an instance of the EntityQueryPagedCollectionView.

Inheritance: IPagedCollectionView, ICollectionView, IEditableCollectionView, INotifyPropertyChanged

Datei anzeigen Open project: IdeaBlade/DevForce.Utilities Class Usage Examples

Private Properties

Property	Type	Description
AddCachingActions	IEnumerable
BeginTrackPageLoading	void
BuildFilteredQuery	EntityQuery
BuildOrderedQuery	EntityQuery
DoGrouping	void
DoInitialLoad	void
EndTrackPageLoading	void
EntityQueryPagedCollectionView	IdeaBlade.Core
GetLookAheadCount	int
GetMemberExpression	System.Linq.Expressions.Expression
GetScalarQuery	IEntityScalarQuery
GetSortDescriptionList	IList
GetTryRefreshPosition	int
IndexToUserState	string
InitFields	void
InitialLoadCore	IEnumerable
IsPageLoadOutstanding	bool
LoadPage	void
LoadPageComplete	void
MakePagedQuery	IEntityQuery
OnPageLoadError	PageLoadErrorEventArgs
ReloadCurrentPage	void
RemoveItemFromList	void
SetCurrentInfo	bool
SetTotalItemCount	void
ShouldLoadLookAheadPage	bool
UserStateToIndex	int

Public Methods

Method	Description
AddNew ( ) : object	Creates an item and adds it to the collection for editing. Calls BeginEdit if the item implements IEditableObject. EntityManager.CreateEntity is used to create the item.
CancelEdit ( ) : void	Cancels editing of the CurrentEditItem. Calls CancelEdit if the item implements IEditableObject.
CancelNew ( ) : void	Cancels editing of the CurrentAddItem. Calls CancelEdit if the item implements IEditableObject.
ClearQueryFilter ( ) : void	Can be used to clear the filter. After clearing the filter, call Refresh to re-query and load the view. Calling either of the SetQueryFilter(IPredicateDescription) overloads with a null value will also clear the filter.
CommitEdit ( ) : void	Completes editing of the CurrentEditItem. Calls EndEdit if the item implements IEditableObject.
CommitNew ( ) : void	Completes editing of the CurrentAddItem. Calls EndEdit if the item implements IEditableObject. EntityManager.AddEntity is called to add the item to the EntityManager cache.
Contains ( object item ) : bool	Returns true if the current page contains the specified item.
DeferRefresh ( ) : IDisposable	Called by bound controls when data should be refreshed.
EditItem ( object item ) : void	Make an item the CurrentEditItem. If the item implements IEditableObject BeginEdit is called.
EntityQueryPagedCollectionView ( EntityQuery query, int pageSize ) : IdeaBlade.Core	Create an instance of this class. Specify the query which will be executed asynchronously to provide paged results. The "load size", the number of items loaded as each page is request, will default to twice the pageSize value.
EntityQueryPagedCollectionView ( EntityQuery query, int pageSize, int loadSize ) : IdeaBlade.Core	Creates an instance of this class. Specify the query which will be executed asynchronously to provide paged results. Set pageSize and loadSize to control the number of items displayed and loaded during a page request. If loadSize is a multiple of pageSize then "look ahead" queries are performed to cache page results.
EntityQueryPagedCollectionView ( EntityQuery query, int pageSize, int loadSize, bool deferLoad, bool addPrimaryKeySort ) : IdeaBlade.Core	Create a new instance of this class. Specify the query which will be executed asynchronously to provide paged results. If the first page should not be immediately loaded set deferLoad to true, and call Refresh() when ready to retrieve data.
GetEnumerator ( ) : IEnumerator	Returns the collection enumerator.
MoveCurrentTo ( object item ) : bool	Selects the indicated item as the CurrentItem.
MoveCurrentToFirst ( ) : bool	Selects the item at position 0 as the CurrentItem.
MoveCurrentToLast ( ) : bool	Selects the last item on the page as the CurrentItem.
MoveCurrentToNext ( ) : bool	Selects the next item as the CurrentItem.
MoveCurrentToPosition ( int position ) : bool	Moves the CurrentPosition to the position indicated.
MoveCurrentToPrevious ( ) : bool	Selects the previous item as the CurrentItem.
MoveToFirstPage ( ) : bool	Move to the first page in the collection.
MoveToLastPage ( ) : bool	Move to the last page in the collection.
MoveToNextPage ( ) : bool	Move to the next page in the collection.
MoveToPage ( int pageIndex ) : bool	Move to the specified 0-based page index.
MoveToPreviousPage ( ) : bool	Move to the previous page in the collection.
Refresh ( ) : void	Re-create the view, using any SortDescriptions, GroupDescriptions and/or filter. Call Refresh if the EntityQueryPagedCollectionView was created with deferred loading.
RefreshCurrentPage ( ) : void	Reload the current page.
Remove ( object item ) : void	Removes an item from the page and calls Delete on the item.
RemoveAt ( int index ) : void	Removes the item at the specified row index and calls Delete on the item.
SetQueryFilter ( System.Linq.Expressions expression ) : void	Set a filter for this view. After setting the filter, call Refresh to re-query and load the view.
SetQueryFilter ( IPredicateDescription predicateDescription ) : void	Set a filter for this view. The filter can be a simple or composite predicate. See the PredicateDescription and PredicateBuilder for more information on building dynamic filter criteria. After setting the filter, call Refresh to re-query and load the view.

Protected Methods

Method	Description
OnCollectionChanged ( NotifyCollectionChangedAction action, object item, int index ) : void	Fires CollectionChanged.
OnCurrentChanged ( ) : void	Fires CurrentChanged.
OnCurrentChanging ( ) : bool	Fires CurrentChanging.
OnPageChanged ( ) : void	Fires PageChanged.
OnPageChanging ( int newPageIndex ) : bool	Fires PageChanging event.
OnPropertyChanged ( string propertyName ) : void	Fires PropertyChanged.

Private Methods

Method	Description
AddCachingActions ( int requestedPageIndex, bool includeRequestedPage ) : IEnumerable
BeginTrackPageLoading ( int pageIndex ) : void
BuildFilteredQuery ( ) : EntityQuery
BuildOrderedQuery ( ) : EntityQuery	Build a query with OrderBy, ThenBy operators.
DoGrouping ( ) : void
DoInitialLoad ( ) : void
EndTrackPageLoading ( int pageIndex ) : void
EntityQueryPagedCollectionView ( EntityQuery query, int pageSize, int loadSize, SortDescriptionCollection sortDescriptors, ObservableCollection groupDescriptors, IPredicateDescription filter ) : IdeaBlade.Core
GetLookAheadCount ( int pageSize, int loadSize ) : int
GetMemberExpression ( System.Linq.Expressions parm, string path ) : Expression
GetScalarQuery ( ) : IEntityScalarQuery	Build a scalar query from the original query.
GetSortDescriptionList ( ) : IList
GetTryRefreshPosition ( ) : int
IndexToUserState ( int index ) : string
InitFields ( ) : void
InitialLoadCore ( int beginPageIndex, bool getTotal ) : IEnumerable
IsPageLoadOutstanding ( int pageIndex ) : bool
LoadPage ( int pageIndex ) : void
LoadPageComplete ( EntityQueryOperation args ) : void
MakePagedQuery ( int requestedPageIndex ) : IEntityQuery	Build a paged query based on the current ordered query.
OnPageLoadError ( IBaseOperation op ) : PageLoadErrorEventArgs
ReloadCurrentPage ( ) : void
RemoveItemFromList ( object item, bool isNew ) : void
SetCurrentInfo ( int newPosition ) : bool
SetTotalItemCount ( int count ) : void
ShouldLoadLookAheadPage ( int pageIndex ) : bool
UserStateToIndex ( object userState ) : int

Method Details

AddNew() public method

Creates an item and adds it to the collection for editing.

Calls BeginEdit if the item implements IEditableObject. EntityManager.CreateEntity is used to create the item.

public AddNew ( ) : object
return	object

CancelEdit() public method

Cancels editing of the CurrentEditItem.

Calls CancelEdit if the item implements IEditableObject.

public CancelEdit ( ) : void
return	void

CancelNew() public method

Cancels editing of the CurrentAddItem.

Calls CancelEdit if the item implements IEditableObject.

public CancelNew ( ) : void
return	void

ClearQueryFilter() public method

Can be used to clear the filter.

After clearing the filter, call Refresh to re-query and load the view.

Calling either of the SetQueryFilter(IPredicateDescription) overloads with a null value will also clear the filter.

public ClearQueryFilter ( ) : void
return	void

CommitEdit() public method

Completes editing of the CurrentEditItem.

Calls EndEdit if the item implements IEditableObject.

public CommitEdit ( ) : void
return	void

CommitNew() public method

Completes editing of the CurrentAddItem.

Calls EndEdit if the item implements IEditableObject. EntityManager.AddEntity is called to add the item to the EntityManager cache.

public CommitNew ( ) : void
return	void

Contains() public method

Returns true if the current page contains the specified item.

public Contains ( object item ) : bool
item	object
return	bool

DeferRefresh() public method

Called by bound controls when data should be refreshed.

public DeferRefresh ( ) : IDisposable
return	IDisposable

EditItem() public method

Make an item the CurrentEditItem.

If the item implements IEditableObject BeginEdit is called.

public EditItem ( object item ) : void
item	object
return	void

EntityQueryPagedCollectionView() public method

Create an instance of this class.

Specify the query which will be executed asynchronously to provide paged results. The "load size", the number of items loaded as each page is request, will default to twice the pageSize value.

public EntityQueryPagedCollectionView ( EntityQuery query, int pageSize ) : IdeaBlade.Core
query	EntityQuery	The query providing the results to the collection
pageSize	int	The number of items to be displayed per page
return	IdeaBlade.Core

EntityQueryPagedCollectionView() public method

Creates an instance of this class.

Specify the query which will be executed asynchronously to provide paged results. Set pageSize and loadSize to control the number of items displayed and loaded during a page request. If loadSize is a multiple of pageSize then "look ahead" queries are performed to cache page results.

public EntityQueryPagedCollectionView ( EntityQuery query, int pageSize, int loadSize ) : IdeaBlade.Core
query	EntityQuery	The query providing the results to the collection
pageSize	int	The number of items to be displayed per page
loadSize	int	The number of items to be loaded when a page is requested
return	IdeaBlade.Core

EntityQueryPagedCollectionView() public method

Create a new instance of this class.

Specify the query which will be executed asynchronously to provide paged results. If the first page should not be immediately loaded set deferLoad to true, and call Refresh() when ready to retrieve data.

public EntityQueryPagedCollectionView ( EntityQuery query, int pageSize, int loadSize, bool deferLoad, bool addPrimaryKeySort ) : IdeaBlade.Core
query	EntityQuery	The query providing the results to the collection
pageSize	int	The number of items to be displayed per page
loadSize	int	The number of items to be loaded when a page is requested
deferLoad	bool	Whether to defer load
addPrimaryKeySort	bool	Whether the data should be sorted on primary key
return	IdeaBlade.Core

GetEnumerator() public method

Returns the collection enumerator.

public GetEnumerator ( ) : IEnumerator
return	IEnumerator

MoveCurrentTo() public method

Selects the indicated item as the CurrentItem.

public MoveCurrentTo ( object item ) : bool
item	object
return	bool

MoveCurrentToFirst() public method

Selects the item at position 0 as the CurrentItem.

public MoveCurrentToFirst ( ) : bool
return	bool

MoveCurrentToLast() public method

Selects the last item on the page as the CurrentItem.

public MoveCurrentToLast ( ) : bool
return	bool

MoveCurrentToNext() public method

Selects the next item as the CurrentItem.

public MoveCurrentToNext ( ) : bool
return	bool

MoveCurrentToPosition() public method

Moves the CurrentPosition to the position indicated.

public MoveCurrentToPosition ( int position ) : bool
position	int
return	bool

MoveCurrentToPrevious() public method

Selects the previous item as the CurrentItem.

public MoveCurrentToPrevious ( ) : bool
return	bool

MoveToFirstPage() public method

Move to the first page in the collection.

public MoveToFirstPage ( ) : bool
return	bool

MoveToLastPage() public method

Move to the last page in the collection.

public MoveToLastPage ( ) : bool
return	bool

MoveToNextPage() public method

Move to the next page in the collection.

public MoveToNextPage ( ) : bool
return	bool

MoveToPage() public method

Move to the specified 0-based page index.

public MoveToPage ( int pageIndex ) : bool
pageIndex	int
return	bool

MoveToPreviousPage() public method

Move to the previous page in the collection.

public MoveToPreviousPage ( ) : bool
return	bool

OnCollectionChanged() protected method

Fires CollectionChanged.

protected OnCollectionChanged ( NotifyCollectionChangedAction action, object item, int index ) : void
action	NotifyCollectionChangedAction
item	object
index	int
return	void

OnCurrentChanged() protected method

Fires CurrentChanged.

protected OnCurrentChanged ( ) : void
return	void

OnCurrentChanging() protected method

Fires CurrentChanging.

protected OnCurrentChanging ( ) : bool
return	bool

OnPageChanged() protected method

Fires PageChanged.

protected OnPageChanged ( ) : void
return	void

OnPageChanging() protected method

Fires PageChanging event.

protected OnPageChanging ( int newPageIndex ) : bool
newPageIndex	int
return	bool

OnPropertyChanged() protected method

Fires PropertyChanged.

protected OnPropertyChanged ( string propertyName ) : void
propertyName	string
return	void

Refresh() public method

Re-create the view, using any SortDescriptions, GroupDescriptions and/or filter.

Call Refresh if the EntityQueryPagedCollectionView was created with deferred loading.

public Refresh ( ) : void
return	void

RefreshCurrentPage() public method

Reload the current page.

public RefreshCurrentPage ( ) : void
return	void

Remove() public method

Removes an item from the page and calls Delete on the item.

public Remove ( object item ) : void
item	object
return	void

RemoveAt() public method

Removes the item at the specified row index and calls Delete on the item.

public RemoveAt ( int index ) : void
index	int
return	void

SetQueryFilter() public method

Set a filter for this view.

After setting the filter, call Refresh to re-query and load the view.

public SetQueryFilter ( System.Linq.Expressions expression ) : void
expression	System.Linq.Expressions
return	void

SetQueryFilter() public method

Set a filter for this view.

The filter can be a simple or composite predicate. See the PredicateDescription and PredicateBuilder for more information on building dynamic filter criteria.

After setting the filter, call Refresh to re-query and load the view.

public SetQueryFilter ( IPredicateDescription predicateDescription ) : void
predicateDescription	IPredicateDescription
return	void