PropertyGridControl.CollectionButtonClick Event

Occurs when a user clicks a collection button. This event allows you to override the button’s default action.

Namespace: DevExpress.Xpf.PropertyGrid

Assembly: DevExpress.Xpf.PropertyGrid.v24.2.dll

NuGet Package: DevExpress.Wpf.PropertyGrid

Declaration

C#

public event EventHandler<CollectionButtonClickEventArgs> CollectionButtonClick

VB.NET

Public Event CollectionButtonClick As EventHandler(Of CollectionButtonClickEventArgs)

Event Data

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

Property	Description
ButtonKind	Gets the collection button‘s type. Inherited from CollectionButtonBaseEventArgs.
DefaultAction	Gets the collection button‘s default action.
Handled	Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs.
OriginalSource	Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs.
RoutedEvent	Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs.
Row	Gets a property grid row. Inherited from PropertyGridRowBaseEventArgs.
Source	Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.
Value	Gets a row’s value. Inherited from PropertyGridRowBaseEventArgs.

The event data class exposes the following methods:

Method	Description
InvokeEventHandler(Delegate, Object)	When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs.
OnSetSource(Object)	When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs.

Remarks

View Example: Specify Custom Collection Edit Actions

You can use the CollectionButtonClick event to initialize a new item whose values depend on the other item’s values. To do this, pass the created item to the e.DefaultAction property as a parameter.

The following code sample adds a new item with the specified ID property when a user clicks the Add Item button:

XAML

<dxprg:PropertyGridControl SelectedObject="{Binding DemoProduct}" 
                           CollectionButtonClick="OnCollectionButtonClick"/>

C#

using DevExpress.Xpf.PropertyGrid;
// ...

void OnCollectionButtonClick(object sender, CollectionButtonClickEventArgs e) {
    if (e.ButtonKind == CollectionButtonKind.Add) {
        var collection = (SupplierList)e.Value;
        e.DefaultAction(new Supplier() { ID = collection.Count == 0 ? 0 : collection.Max(x => x.ID) + 1, Name = "", Phone = "" });
        e.Handled = true;
    }
}

VB.NET

Imports DevExpress.Xpf.PropertyGrid
' ...

Private Sub OnCollectionButtonClick(ByVal sender As Object, ByVal e As CollectionButtonClickEventArgs)
    If e.ButtonKind = CollectionButtonKind.Add Then
        Dim collection = CType(e.Value, SupplierList)
        e.DefaultAction(New Supplier() With {
            .ID = If(collection.Count = 0, 0, collection.Max(Function(x) x.ID) + 1),
            .Name = "",
            .Phone = ""
        })
        e.Handled = True
    End If
End Sub

Refer to the following help topic for more information: Collection Definitions.