ListViewProcessCurrentObjectController.CustomProcessSelectedItem Event

Occurs when the ListViewShowObject Action (ListViewProcessCurrentObjectController.ProcessCurrentObjectAction) is about to be executed.

Namespace: DevExpress.ExpressApp.SystemModule

Assembly: DevExpress.ExpressApp.v19.1.dll

Declaration

C#

public event EventHandler<CustomProcessListViewSelectedItemEventArgs> CustomProcessSelectedItem

VB.NET

Public Event CustomProcessSelectedItem As EventHandler(Of CustomProcessListViewSelectedItemEventArgs)

Event Data

The CustomProcessSelectedItem event's data class is DevExpress.ExpressApp.SystemModule.CustomProcessListViewSelectedItemEventArgs.

Remarks

When an end-user double-clicks an object in the current List View, or presses ENTER for a selected object, the ListViewShowObject Action is executed. This Action invokes a Detail View for the selected object. You may need to execute a custom Action instead of the ListViewShowObject Action in a certain List View. For instance, the Windows Forms ReportsController invokes the Report Designer, and the ASP.NET ReportsController invokes the Report Viewer for the selected object. To replace the default ListViewShowObject Action with a custom one, handle the CustomProcessSelectedItem event. Set the handler’s CustomProcessListViewSelectedItemEventArgs.Handled parameter to true to prevent execution of the default Action after your Action has been executed. To access the object currently selected in the List View, use the handler’s CustomProcessListViewSelectedItemEventArgs.InnerArgs.CurrentObject parameter.

Code snippet below demonstrates the Controller that shows a custom Detail View using the CustomProcessSelectedItem event.

C#

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.SystemModule;
// ...
public class ProcessContactListViewRowController : ViewController {
    public ProcessContactListViewRowController() {
        TargetViewId = "Contact_ListView";
    }
    protected override void OnActivated() {
        base.OnActivated();
        ListViewProcessCurrentObjectController listProcessController = Frame.GetController<ListViewProcessCurrentObjectController>();
        if(listProcessController != null)
            listProcessController.CustomProcessSelectedItem += ProcessContactListViewRowController_CustomProcessSelectedItem;        
    }
    void ProcessContactListViewRowController_CustomProcessSelectedItem(
        object sender, CustomProcessListViewSelectedItemEventArgs e) {
        Contact currentContact = (Contact)e.InnerArgs.CurrentObject;
        if (currentContact.Position != null && currentContact.Position.Title == "Manager") {
            IObjectSpace objectSpace = Application.CreateObjectSpace(currentContact.GetType());
            e.InnerArgs.ShowViewParameters.CreatedView = Application.CreateDetailView(objectSpace, "Contact_DetailView_Manager", true, objectSpace.GetObject(currentContact));
            e.Handled = true;
        }
    }
    protected override void OnDeactivated() {
        base.OnDeactivated();
        Frame.GetController<ListViewProcessCurrentObjectController>().CustomProcessSelectedItem -= ProcessContactListViewRowController_CustomProcessSelectedItem;
    }
}

VB.NET

Imports DevExpress.ExpressApp
Imports DevExpress.ExpressApp.SystemModule
' ...
Public Class ProcessContactListViewRowController
    Inherits ViewController

    Public Sub New()
        TargetViewId = "Contact_ListView"
    End Sub
    Protected Overrides Sub OnActivated()
        MyBase.OnActivated()
        Dim listProcessController As ListViewProcessCurrentObjectController = Frame.GetController(Of ListViewProcessCurrentObjectController)()
        If (Not (listProcessController Is Nothing)) Then
            AddHandler listProcessController.CustomProcessSelectedItem, AddressOf ProcessContactListViewRowController_CustomProcessSelectedItem
        End If        
    End Sub
    Private Sub ProcessContactListViewRowController_CustomProcessSelectedItem(ByVal sender As Object, ByVal e As CustomProcessListViewSelectedItemEventArgs)
        Dim currentContact As Contact = CType(e.InnerArgs.CurrentObject, Contact)
        If currentContact.Position IsNot Nothing AndAlso currentContact.Position.Title = "Manager" Then
            Dim objectSpace As IObjectSpace = Application.CreateObjectSpace(currentContact.GetType())
            e.InnerArgs.ShowViewParameters.CreatedView = Application.CreateDetailView( _
            objectSpace, "Contact_DetailView_Manager", True, objectSpace.GetObject(currentContact))
            e.Handled = True
        End If
    End Sub
    Protected Overrides Sub OnDeactivated()
        MyBase.OnDeactivated()
        RemoveHandler Frame.GetController(Of ListViewProcessCurrentObjectController)().CustomProcessSelectedItem, AddressOf ProcessContactListViewRowController_CustomProcessSelectedItem
    End Sub
End Class

Note

The WebApplication.OptimizationSettings.AllowFastProcessListViewRecordActions option can influence the CustomProcessSelectedItem event. Disable this option as described in the Faster rendering and other performance optimizations for popular Web UI scenarios in XAF KB article, if you face any difficulty when custom processing selected items is implemented in this event handler (e.g., difficulty with the default UI elements rendering or behavior).

More examples of handling the CustomProcessSelectedItem event are provided in the How to: Replace a List View’s Default Action topic.

To completely disable the GridListEditor‘s management of double clicks, set the GridListEditor.ProcessSelectedItemByDoubleClick property to false.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the CustomProcessSelectedItem event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

XAF_how-to-replace-a-list-views-default-action-e3275/CS/ReplaceDefaultActionInListView.Module.Win/WriteMailController.cs#L31

if (processCurrentObjectController != null) {
    processCurrentObjectController.CustomProcessSelectedItem +=
        processCurrentObjectController_CustomProcessSelectedItem;

XAF_how-to-show-a-large-image-in-a-popup-when-a-small-image-in-a-list-view-column-is-clicked-e2828/CS/Solution15.Module.Win/ShowImageController.cs#L18

    controller = Frame.GetController<ListViewProcessCurrentObjectController>();
    controller.CustomProcessSelectedItem += new EventHandler<CustomProcessListViewSelectedItemEventArgs>(controller_CustomProcessSelectedItem);
}

VB.NET

XAF_how-to-replace-a-list-views-default-action-e3275/VB/ReplaceDefaultActionInListView.Module.Win/WriteMailController.vb#L31

If processCurrentObjectController IsNot Nothing Then
    AddHandler processCurrentObjectController.CustomProcessSelectedItem, AddressOf processCurrentObjectController_CustomProcessSelectedItem
End If

XAF_how-to-show-a-large-image-in-a-popup-when-a-small-image-in-a-list-view-column-is-clicked-e2828/VB/Solution15.Module.Win/ShowImageController.vb#L20

    controller = Frame.GetController(Of ListViewProcessCurrentObjectController)()
    AddHandler controller.CustomProcessSelectedItem, AddressOf controller_CustomProcessSelectedItem
End Sub