ViewController<ViewType> Class

A base class for generic View Controllers.

Assembly : DevExpress.ExpressApp.v25.2.dll

NuGet Package : DevExpress.ExpressApp

Declaration

C#
VB.NET

csharp

public abstract class ViewController<ViewType> :
    ViewController
    where ViewType : View

Public MustInherit Class ViewController(Of ViewType As View)
    Inherits ViewController

Type Parameters

Name	Description
ViewType

The XAF View subtype (for example, DetailView, ListView, or DashboardView) that this Controller targets.

Remarks

ViewController<ViewType> is the generic version of the ViewController class. The ViewType type parameter specifies the View subtype that the Controller targets. XAF assigns ViewType to the ViewController.TypeOfView property, so the Controller is activated only for that View type. The ViewController.View property is typed as ViewType, so you can access the View without an explicit cast.

The following code snippet demonstrates a custom View Controller derived from the generic ViewController.

csharp

using DevExpress.Blazor;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Blazor.Editors;
using MainDemo.Module.BusinessObjects;

namespace MainDemo.Blazor.Server.Controllers;

public sealed class EmlployeeListViewController : ObjectViewController<ListView, Employee> {
    protected override void OnViewControlsCreated() {
        base.OnViewControlsCreated();
        if(View.Editor is DxGridListEditor gridListEditor) {
            // ...
        }
    }
}

Note

CodeRush allows you to add Actions and Controllers with a few keystrokes. To learn about the Code Templates for XAF , refer to the following help topic: XAF Templates.

Visual Studio Designer does not support generic components and cannot be used to design generic Controllers. As a workaround, declare an intermediate non-generic base class that derives from a generic Controller and is decorated with the DesignerCategoryAttribute. Then derive your custom Controller from that intermediate class. The following code snippet illustrates this approach.

csharp

using System.ComponentModel;
using DevExpress.Blazor;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Blazor.Editors;
using MainDemo.Module.BusinessObjects;

namespace MainDemo.Blazor.Server.Controllers;

[DesignerCategory("Component")]
public abstract class MyIntermediateListViewController : ObjectViewController<ListView, Employee> {
    //...
}

public sealed class MyViewController : MyIntermediateListViewController {
    //...
}