wpf-devexpress-dot-xpf-dot-propertygrid-dot-propertygridcontrol-c4b4b838.md
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.v25.2.dll
NuGet Package : DevExpress.Wpf.PropertyGrid
public event EventHandler<CollectionButtonClickEventArgs> CollectionButtonClick
Public Event CollectionButtonClick As EventHandler(Of CollectionButtonClickEventArgs)
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. |
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:
<dxprg:PropertyGridControl SelectedObject="{Binding DemoProduct}"
CollectionButtonClick="OnCollectionButtonClick"/>
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;
}
}
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.
The following code snippet (auto-collected from DevExpress Examples) contains a reference to the CollectionButtonClick 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.
wpf-property-grid-specify-custom-collection-edit-actions/CS/MainWindow.xaml#L11
CollectionButtonsVisibility="OnCollectionButtonsVisibility"
CollectionButtonClick="OnCollectionButtonClick"/>
</dx:ThemedWindow>
wpf-property-grid-specify-custom-collection-edit-actions/CS/obj/Debug/net472/MainWindow.g.cs#L99
#line 11 "..\..\..\MainWindow.xaml"
this.propertyGrid.CollectionButtonClick += new System.EventHandler<DevExpress.Xpf.PropertyGrid.CollectionButtonClickEventArgs>(this.OnCollectionButtonClick);
#ExternalSource("..\..\..\MainWindow.xaml",11)
AddHandler Me.propertyGrid.CollectionButtonClick, New System.EventHandler(Of DevExpress.Xpf.PropertyGrid.CollectionButtonClickEventArgs)(AddressOf Me.OnCollectionButtonClick)
See Also