RecordsNavigationController Class
A ViewController descendant that contains the Previous Object and Next Object Actions.
Namespace: DevExpress.ExpressApp.SystemModule
Assembly: DevExpress.ExpressApp.v24.2.dll
NuGet Package: DevExpress.ExpressApp
#Declaration
#Remarks
The RecordsNavigationController
displays the Previous Object and Next Object Actions.
- ASP.NET Core Blazor
- Windows Forms
- ASP.NET Web Forms
To ascertain whether the Controller is active, use the Controller.Active property. If you need to know the reason for its deactivation or activation at runtime, use the DiagnosticInfo Action.
Information about the RecordsNavigationController
and its Previous Object and Next Object Actions is available in the Application Model‘s ActionDesign node. To access the node, use the Model Editor.
#Order Providers
XAF activates RecordsNavigationController
for all Views. This controller uses an OrderProviderSource
to obtain an OrderProvider
. These objects determine which collection to use and how to fetch the required objects from the collection when a user executes Next Object or Previous Object Actions.
Order Providers implement the following members of the IOrderProvider
interface: GetObjectByIndex
and GetOrderedObjects
. XAF supports several Order Providers that implement either the IObjectOrderProvider
or IKeyOrderProvider
interface. Both interfaces are IOrderProvider
interface descendants. The IObjectOrderProvider
interface includes the GetIndexByObject
method, while the IKeyOrderProvider
includes the GetIndexByObjectKey
method.
#ListEditorOrderProvider
Implements IObjectOrderProvider
.
Works with a List View that you pass to it in its constructor. Uses the corresponding methods of its ControlOrderProvider
- the List View’s Editor that implements the IControlOrderProvider
interface. The built-in List Editors implement this interface (DxGridListEditor, GridListEditor, ASPxGridListEditor, SchedulerListEditorBase and TreeListEditor). If the current editor does not implement these the required interface methods, XAF uses DefaultOrderProvider
. This Order Provider is passed to the ListEditorOrderProvider
in its constructor.
Used when XAF activates the RecordsNavigationController
for a List View.
#DefaultOrderProvider
Implements IObjectOrderProvider
.
Works with any View that you pass to it in its constructor. In case of a List View, this Order Provider uses the DataSource
of the ListEditor
. In case of a Detail View, the GetObjectByIndex
and GetOrderedObjects
methods return null
, and the GetIndexByObject
method returns -1
.
Used when XAF activates the RecordsNavigationController
for a List View, but the View’s Editor does not implement the IControlOrderProvider
interface or when XAF activates the RecordsNavigationController
for a Detail View.
#NullOrderProvider
Implements IObjectOrderProvider
.
The GetObjectByIndex
and GetOrderedObjects
methods return null
, and the GetIndexByObject
method returns -1
.
Used by the ListEditorOrderProvider
when the specified DefaultOrderProvider
is null
.
#StandaloneOrderProvider
Implements IKeyOrderProvider
.
Works with the ordered list of objects that you pass to it in its constructor.
Used when the current RecordsNavigationController
is deactivated. The previously used Order Provider passes the objects it worked with to this Order Provider. This is required to support a Detail View’s RecordsNavigationController
that uses the Order Provider of a List View’s RecordsNavigationController
.
By default, when XAF activates the RecordsNavigationController
for a List View, it passes this View to the Order Provider. The Next Object and Previous Object Actions can then navigate through the List View’s objects. When the RecordsNavigationController
is activated for a standalone Detail View, there is no collection to navigate through, so the Next Object and Previous Object Actions are disabled. However, you can also invoke a Detail View in a separate Window to display objects selected in a List View. RecordsNavigationController
handles this scenario in a special manner. The OrderProviderSource
used by the List View’s RecordsNavigationController
is assigned to the RecordsNavigationController.OrderProviderSource property of the Detail View’s RecordsNavigationController
. Therefore, XAF uses the List View’s collection for navigation in the Detail View, since the Order Provider works with the List View.
You can inherit from this Controller or subscribe to its events to modify its behavior. In addition, you can use the RecordsNavigationController.NextObjectAction and RecordsNavigationController.PreviousObjectAction properties to access the Controller’s Next Object and Previous Object Actions and modify their behavior.
#RecordsNavigationController Behavior Customization
If you need to override the behavior of RecordsNavigationController
, inherit from one of the following classes:
- ASP.NET Core Blazor
DevExpress.ExpressApp.Blazor.SystemModule.BlazorRecordsNavigationController
- Windows Forms
DevExpress.ExpressApp.SystemModule.RecordsNavigationController
- ASP.NET Web Forms
DevExpress.ExpressApp.Web.SystemModule.WebRecordsNavigationController
You can override the following methods:
Method | What triggers this method? | Description |
---|---|---|
| The Next Object Action. | The Next Object Action’s Simple |
| The Previous Object Action. | The Action’s Simple |
| The Xaf | If the target View is a Detail View displayed in a separate Window, this method creates an |
|
| Returns a newly created |
|
| Updates the Next Object and Previous Object Action’s Active and Enabled state. |