XafApplication.ViewCreating Event

Occurs when creating a View.

Namespace: DevExpress.ExpressApp

Assembly: DevExpress.ExpressApp.v23.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

public event EventHandler<ViewCreatingEventArgs> ViewCreating

VB.NET

Public Event ViewCreating As EventHandler(Of ViewCreatingEventArgs)

Event Data

The ViewCreating event's data class is ViewCreatingEventArgs. The following properties provide information specific to this event:

Property	Description
IsRoot	Indicates whether a root View must be created.
ObjectSpace	Returns the Object Space to be used when creating a new View.
View	Specifies a custom View created in a XafApplication.DetailViewCreating or XafApplication.ListViewCreating event.
ViewID	Returns the ID of the created View.

Remarks

Handle this event to provide a custom View instead of a default one. Use the handler’s ViewCreatingEventArgs.View parameter to get information on the View being created. To do this, use the application’s XafApplication.FindModelView method passing the View ID as a parameter.

To specify the Detail View’s current object use the handler’s DetailViewCreatingEventArgs.Obj parameter. Create the Detail View in the Object Space passed as the handler’s ViewCreatingEventArgs.ObjectSpace parameter.

To create a List View, use the collection source passed as the handler’s ListViewCreatingEventArgs.CollectionSource parameter. To specify whether the List View is root, use the handler’s ViewCreatingEventArgs.IsRoot parameter.

The following example demonstrates how to handle the ViewCreating event:

C#

using DevExpress.ExpressApp;

namespace MySolution.Module.Controllers {
    public class MyWindowController : WindowController {
        public MyWindowController() {
            TargetWindowType = WindowType.Main;
        }
        protected override void OnActivated() {
            base.OnActivated();
            Application.ViewCreating += Application_ViewCreating;
        }
        void Application_ViewCreating(object sender, ViewCreatingEventArgs e) {
            if (e.ViewID == "Contact_DetailView") {
                var os = Application.CreateObjectSpace(typeof(MyTask));
                var obj = os.CreateObject<MyTask>();
                obj.Subject = "New MyTask";
                var view = Application.CreateDetailView(os, obj);
                e.View = view;
            }
        }
        protected override void OnDeactivated() {
            base.OnDeactivated();
            Application.ViewCreating -= Application_ViewCreating;
        }
    }
}

VB.NET

Imports DevExpress.ExpressApp
Imports MySolutionName.[Module].BusinessObjects

Namespace MySolutionName.[Module].Controllers
    Public Class MyWindowController
        Inherits WindowController
        Public Sub New()
            TargetWindowType = WindowType.Main
        End Sub
        Protected Overrides Sub OnActivated()
            MyBase.OnActivated()
            AddHandler Application.ViewCreating, AddressOf Application_ViewCreating
        End Sub
        Private Sub Application_ViewCreating(ByVal sender As Object, ByVal e As ViewCreatingEventArgs)
            If e.ViewID = "Contact_DetailView" Then
                Dim os As IObjectSpace = Application.CreateObjectSpace(GetType(MyTask))
                Dim obj As MyTask = os.CreateObject(Of MyTask)()
                obj.Subject = "New MyTask"
                Dim view As DetailView = Application.CreateDetailView(os, obj)
                e.View = view
            End If
        End Sub
        Protected Overrides Sub OnDeactivated()
            MyBase.OnDeactivated()
            RemoveHandler Application.ViewCreating, AddressOf Application_ViewCreating
        End Sub
    End Class
End Namespace

Note

If DetailView.UseAsyncLoading is set to true, note the following:

• when you open a Detail View from the Navigation, the DetailViewCreatingEventArgs.Obj argument of the ViewCreating event is set to null;
• when you open a Detail View from a List View (by double-clicking a record or using the OpenObject Action), the DetailViewCreatingEventArgs.Obj argument of the ViewCreating event is set to the object from the List View’s Object Space.