View.SelectionChanged Event

Occurs after changing a View’s selected objects.

Namespace: DevExpress.ExpressApp

Assembly: DevExpress.ExpressApp.v20.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

public event EventHandler SelectionChanged

VB.NET

Public Event SelectionChanged As EventHandler

Event Data

The SelectionChanged event's data class is EventArgs.

Remarks

This event is raised in methods of the View class descendants:

• DetailView

  The SelectionChanged event occurs after changing the current object as a result of setting a value to the DetailView.CurrentObject method.

• ListView

  The SelectionChanged event is raised when the selected objects are changed in the ListView.Editor.

The example below demonstrates how to change a SimpleAction‘s caption when the selected object changes.

C#

using System;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Actions;
using DevExpress.Persistent.Base;
using MainDemo.Module.BusinessObjects;
// ...
public class ActionCaptionController : ViewController {
    private SimpleAction objectAction;
    private void UpdateActionCaption() {
        objectAction.Caption = CalculateActionCaption();
    }
    private string CalculateActionCaption() {
        Contact currentObject = (Contact)View.CurrentObject;
        if(currentObject != null) {
            return currentObject.FullName;
        }
        return "Object Action";
    }
    private void View_SelectionChanged(object sender, EventArgs e) {
        UpdateActionCaption();
    }
    protected override void OnActivated() {
        base.OnActivated();
        UpdateActionCaption();
        View.SelectionChanged += View_SelectionChanged;
    }
    protected override void OnDeactivated() {
        View.SelectionChanged -= View_SelectionChanged;
        base.OnDeactivated();
    }
    public ActionCaptionController() {
        TargetObjectType = typeof(Contact);
        objectAction = new SimpleAction(this, "ObjectAction", PredefinedCategory.Edit);
    }
}

VB.NET

Imports System
Imports DevExpress.ExpressApp
Imports DevExpress.ExpressApp.Actions
Imports DevExpress.Persistent.Base
Imports MainDemo.Module.BusinessObjects

Public Class ActionCaptionController
    Inherits ViewController
    Private objectAction As SimpleAction
    Private Sub UpdateActionCaption()
        objectAction.Caption = CalculateActionCaption()
    End Sub
    Private Function CalculateActionCaption() As String
        Dim currentObject As Contact = CType(View.CurrentObject, Contact)
        If currentObject IsNot Nothing Then
            Return currentObject.FullName
        End If
        Return "Object Action"
    End Function
    Private Sub View_SelectionChanged(ByVal sender As Object, ByVal e As EventArgs)
        UpdateActionCaption()
    End Sub
    Protected Overrides Sub OnActivated()
        MyBase.OnActivated()
        UpdateActionCaption()
        AddHandler View.SelectionChanged, AddressOf View_SelectionChanged
    End Sub
    Protected Overrides Sub OnDeactivated()
        RemoveHandler View.SelectionChanged, AddressOf View_SelectionChanged
        MyBase.OnDeactivated()
    End Sub
    Public Sub New()
        TargetObjectType = GetType(Contact)
        objectAction = New SimpleAction(Me, "ObjectAction", PredefinedCategory.Edit)
    End Sub
End Class

Note

To run this code, add the DevExpress.ExpressApp.XtraGrid.v20.2.dll assembly to References.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the SelectionChanged 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-access-objects-selected-in-the-current-view-e3016/CS/SelectedObjects.Module/MyConfirmationController.cs#L18

defaultMessage = deleteObjectsViewController.DeleteAction.GetFormattedConfirmationMessage();
View.SelectionChanged += View_SelectionChanged;
UpdateConfirmationMessage();

XAF_how-to-implement-dependent-views-in-a-dashboardview-filter-based-on-selection-e4916/CS/Solution3.Module/Controllers/DashboardFilterController.cs#L32

if(innerListView != null) {
    innerListView.SelectionChanged -= innerListView_SelectionChanged;
    innerListView.SelectionChanged += innerListView_SelectionChanged;

XAF_categorizedlisteditor-how-to-show-subcategory-items-when-a-parent-category-is-selected-e1415/CS/WinSample.Module.Win/MyCategorizedListEditor.cs#L20

base.OnControlsCreated();
CategoriesListView.SelectionChanged += new EventHandler(CategoriesListView_SelectionChanged);
ObjectTreeList objectTreeList = CategoriesListView.Editor.Control as ObjectTreeList;

VB.NET

XAF_how-to-access-objects-selected-in-the-current-view-e3016/VB/SelectedObjects.Module/MyConfirmationController.vb#L20

defaultMessage = deleteObjectsViewController.DeleteAction.GetFormattedConfirmationMessage()
AddHandler View.SelectionChanged, AddressOf View_SelectionChanged
UpdateConfirmationMessage()

XAF_how-to-implement-dependent-views-in-a-dashboardview-filter-based-on-selection-e4916/VB/Solution3.Module/Controllers/DashboardFilterController.vb#L34

If innerListView IsNot Nothing Then
    RemoveHandler innerListView.SelectionChanged, AddressOf innerListView_SelectionChanged
    AddHandler innerListView.SelectionChanged, AddressOf innerListView_SelectionChanged

XAF_categorizedlisteditor-how-to-show-subcategory-items-when-a-parent-category-is-selected-e1415/VB/WinSample.Module.Win/MyCategorizedListEditor.vb#L24

MyBase.OnControlsCreated()
AddHandler CategoriesListView.SelectionChanged, AddressOf CategoriesListView_SelectionChanged
Dim objectTreeList As ObjectTreeList = TryCast(CategoriesListView.Editor.Control, ObjectTreeList)