events.md

title	page_title	description	position	slug
Events	.NET MAUI TreeView Documentation - Events	Review TreeView events that are raised when item is tapped, selected and source is changed.	7	treeview-events

.NET MAUI TreeView Events

The .NET MAUI TreeView emits a set of events that allow you to configure the component's behavior in response to specific user actions.

The .NET MAUI TreeView exposes the following events:

• ItemTapped—Raised when an item is tapped. The ItemTapped event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A ItemViewTappedEventArgs object, which has a reference to:
    • the tapped item through its Item(object) property.
    • the tapped View(ItemView).
    • the Handled(bool) property—Indicates whether the event handler has already handled the tap event. When set to true, the default handling of the tap event is not executed. When set to false, the default handling of the tap event is executed.

  On Android and iOS, when tapping the TreeView item, the item gets expanded. On WinUI and MacCatalyst, the item gets expanded when tapping on the arrow >.

• ItemHolding—Raised when an item is held. The ItemHolding event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A ItemViewHoldingEventArgs object which has a reference to:
    • the tapped item through its Item(object) property.
    • the tapped View(ItemView).
    • the Handled(bool) property—Indicates whether the event handler has already handled the hold event. When set to true, the default handling of the hold event is not executed. When set to false, the default handling of the hold event is executed.

• ItemsSourceChanged—Raised when ItemsSource has changed. The ItemsSourceChanged event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • An EventHandler object.

• SelectionChanged—Raised when the current selection changes. The SelectionChanged event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A EventArgs object, which provides information on the SelectionChanged event.

• LoadChildrenOnDemand—Raised when loading an item on demand. The LoadChildrenOnDemand event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A TreeViewLoadChildrenOnDemandEventArgs object, which has a reference to:
    • the item through its Item(object) property.

• ItemChecked—Raised when an item is checked after a user interaction. The ItemChecked event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A TreeViewItemViewInteractionEventArgs object which has a reference to:
    • the tapped item through its Item(object) property.
    • the tapped View(ItemView).

• ItemUnchecked—Raised when an item is unchecked after a user interaction. The ItemUnchecked event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A TreeViewItemViewInteractionEventArgs object which has a reference to:
    • the tapped item through its Item(object) property.
    • the tapped View(ItemView).

• ItemExpanded—Raised when an item is expanded after a user interaction. The ItemExpanded event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A TreeViewItemViewInteractionEventArgs object which has a reference to:
    • the tapped item through its Item(object) property.
    • the tapped View(ItemView).

• ItemCollapsed—Raised when an item is collapsed after a user interaction. The ItemCollapsed event handler receives two parameters:

  • The sender argument, which is of type object, but can be cast to the RadTreeView type.
  • A TreeViewItemViewInteractionEventArgs object which has a reference to:
    • the tapped item through its Item(object) property.
    • the tapped View(ItemView).

Using the ItemTapped Event

The following example demonstrates how to use the ItemTapped event:

1. Define the RadTreeView control:

2. Add the ItemTapped event:

3. Add the data model:

4. Add the ViewModel:

This is the result on Android:

Using the SelectionChanged Event

The following example demonstrates how to use the SelectionChanged event:

1. Define the RadTreeview control:

2. Add the ItemTapped event:

3. Add the data model:

4. Add the ViewModel:

This is the result on Android:

For a runnable example demonstrating the TreeView events, see the [SDKBrowser Demo Application]({%slug sdkbrowser-app%}) and go to TreeView > Events.

See Also

• [Expand and Collapse TreeView Items]({%slug treeview-expand-collapse%})
• [CheckBoxes in TreeView]({%slug treeview-checkboxes%})
• [Styling the TreeView Item]({%slug treeview-item-style%})
• [Scrolling options]({%slug treeview-scrolling%})
• [Multiple and Single Selection]({%slug treeview-selection%})
• [Available Commands in .NET MAUI TreeView]({%slug treeview-commands%})