ViewItem Class

Represents a base class for View Items.

Namespace: DevExpress.ExpressApp.Editors

Assembly: DevExpress.ExpressApp.v18.2.dll

Declaration

public abstract class ViewItem :
    IDisposable
Public MustInherit Class ViewItem
    Implements IDisposable

The ViewItem class implements basic functionality for items that can be contained in a Detail View. This functionality includes:

To access the Detail View in which a View Item is contained, use the ViewItem.View property.

The eXpressApp Framework ships with the following descendants of the ViewItem class:

To implement a custom View Item, inherit from the ViewItem class. The following protected members that are not described in the documentation can be overridden:

Member Description
CreateControlCore Called by the ViewItem.CreateControl method. You should return the control that will represent your View Item in a UI.
SaveModelCore Called by the ViewItem.SaveModel method. You can override it to save the settings of a View Item and its control to the Application Model. This allows display of the View Item in the same manner as it was before it was recreated.
Dispose Called by the ViewItem.Dispose method. Override it if you need to dispose custom allocated resources.
OnCurrentObjectChanging and OnCurrentObjectChanged Called when the ViewItem.CurrentObject property is changed.
OnControlCreating and OnControlCreated Called when a control (see ViewItem.Control) is created. Raise the ViewItem.ControlCreating and ViewItem.ControlCreated events.
Note

A custom View Item should be implemented in a module project and decorated with the ViewItemAttribute. In this instance, it will be loaded to the Application Model, which means that you will be able to use it in a UI. Additionally, the module should be UI-specific, because the View Item creates a UI-specific control.

For details on View Items and basics on how to implement custom ones, refer to the View Items and Implement Custom View Items topics. For an example of a custom View Item, refer to the How to: Implement a View Item topic.

To access a View Item of the View for which a Controller is activated, handle the Controller.Activated and ViewItem.ControlCreated events, as it is demonstrated in the Access Editor Settings tutorial.

See Also