View.CurrentObjectChanged Event

Occurs after changing a View’s focused object (not an object’s property value).

Namespace: DevExpress.ExpressApp

Assembly: DevExpress.ExpressApp.v20.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

public event EventHandler CurrentObjectChanged

VB.NET

Public Event CurrentObjectChanged As EventHandler

Event Data

The CurrentObjectChanged event's data class is EventArgs.

Remarks

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

• DetailView

  The CurrentObjectChanged event is raised after a currently displayed object (the DetailView.CurrentObject property value) is changed. For example, this occurs when you navigate to another object using the NextObjectAction or PreviousObjectAction.

• ListView

  The CurrentObjectChanged event is raised when the focused object is changed in a ListView.Editor.

Important

Do not mix a View’s focused object changes with property value changes. To track object instance’s changes, handle the IObjectSpace.ObjectChanged, INotifyPropertyChanged.PropertyChanged or other suitable events.

The following example demonstrates how to use the CurrentObjectChanged event to make a View read-only:

C#

public class MyController : ViewController {
    protected override void OnActivated() {
        base.OnActivated();
        View.CurrentObjectChanged += View_CurrentObjectChanged;
        View_CurrentObjectChanged(View, new EventArgs());
    }
    private void View_CurrentObjectChanged(object sender, EventArgs e) {
       if (View.CurrentObject is Task) {
            View.AllowEdit["CurrentUser"] = ((Task)View.CurrentObject).Owner.Id == SecuritySystem.CurrentUserId;
       }
    }
    protected override void OnDeactivated() {           
        View.CurrentObjectChanged -= View_CurrentObjectChanged;
        base.OnDeactivated();
    }
}

VB.NET

Public Class MyController
    Inherits ViewController
    Protected Overrides Sub OnActivated()
        MyBase.OnActivated()
        AddHandler View.CurrentObjectChanged, AddressOf View_CurrentObjectChanged
        View_CurrentObjectChanged(View, New EventArgs())
    End Sub
    Private Sub View_CurrentObjectChanged(ByVal sender As Object, ByVal e As EventArgs)
       If TypeOf View.CurrentObject Is Task Then
           View.AllowEdit("CurrentUser") = CType(View.CurrentObject, Task).Owner.Id = SecuritySystem.CurrentUserId
       End If
    End Sub
    Protected Overrides Sub OnDeactivated()
        RemoveHandler View.CurrentObjectChanged, AddressOf View_CurrentObjectChanged
        MyBase.OnDeactivated()
    End Sub
End Class

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the CurrentObjectChanged 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-a-nested-listview-from-the-parent-detailviews-controller-and-vice-versa-e3977/CS/WinExample.Module/Controllers/AccessParentDetailViewController.cs#L24

base.OnActivated();
View.CurrentObjectChanged += new EventHandler(View_CurrentObjectChanged);
UpdateDetailViewCaption();

XAF_validation-how-to-highlight-invalid-properties-when-the-view-is-shown-e1524/CS/DXSample.Module/ImmediateValidationController.cs#L26

    ObjectSpace.ObjectReloaded += ObjectSpace_ObjectReloaded;
    View.CurrentObjectChanged += View_CurrentObjectChanged;
}

XAF_how-to-dynamically-change-mask-settings-based-on-the-current-object-t236972/CS/ChangeEditMask.Module/Controllers/ChangeMaskControllerBase.cs#L13

base.OnActivated();
View.CurrentObjectChanged += View_CurrentObjectChanged;
ObjectSpace.ObjectChanged += ObjectSpace_ObjectChanged;

XAF_categorizedlisteditor-how-to-show-subcategory-items-when-a-parent-category-is-selected-e1415/CS/WinSample.Module.Win/MyCategorizedListEditor.cs#L69

public override void Dispose() {
    this.CategoriesListView.CurrentObjectChanged -= new EventHandler(CategoriesListView_SelectionChanged);
    locker.LockedChanged -= new EventHandler<LockedChangedEventArgs>(locker_LockedChanged);

XAF_how-to-apply-another-appearance-to-reviewed-objects-e1386/CS/DXExample.Module/MarkAsReadViewController.cs#L21

    AddObjectToUserBOs(!ObjectSpace.IsModified);
    View.CurrentObjectChanged += new EventHandler(View_CurrentObjectChanged);
}

VB.NET

XAF_how-to-access-a-nested-listview-from-the-parent-detailviews-controller-and-vice-versa-e3977/VB/WinExample.Module/Controllers/AccessParentDetailViewController.vb#L26

MyBase.OnActivated()
AddHandler View.CurrentObjectChanged, AddressOf View_CurrentObjectChanged
UpdateDetailViewCaption()

XAF_validation-how-to-highlight-invalid-properties-when-the-view-is-shown-e1524/VB/DXSample.Module/ImmediateValidationController.vb#L29

    AddHandler ObjectSpace.ObjectReloaded, AddressOf ObjectSpace_ObjectReloaded
    AddHandler View.CurrentObjectChanged, AddressOf View_CurrentObjectChanged
End Sub

XAF_how-to-dynamically-change-mask-settings-based-on-the-current-object-t236972/VB/ChangeEditMask.Module/Controllers/ChangeMaskControllerBase.vb#L13

MyBase.OnActivated()
AddHandler View.CurrentObjectChanged, AddressOf View_CurrentObjectChanged
AddHandler ObjectSpace.ObjectChanged, AddressOf ObjectSpace_ObjectChanged

XAF_categorizedlisteditor-how-to-show-subcategory-items-when-a-parent-category-is-selected-e1415/VB/WinSample.Module.Win/MyCategorizedListEditor.vb#L73

Public Overrides Sub Dispose()
    RemoveHandler CategoriesListView.CurrentObjectChanged, AddressOf CategoriesListView_SelectionChanged
    RemoveHandler locker.LockedChanged, AddressOf locker_LockedChanged

XAF_how-to-apply-another-appearance-to-reviewed-objects-e1386/VB/DXExample.Module/MarkAsReadViewController.vb#L23

    AddObjectToUserBOs((Not ObjectSpace.IsModified))
    AddHandler View.CurrentObjectChanged, AddressOf View_CurrentObjectChanged
End Sub