UIElement.PointerWheelChanged event

Occurs when the delta value of a pointer wheel changes.

Syntax

public event PointerEventHandler PointerWheelChanged

<uielement PointerWheelChanged = "eventhandler" .../>

Event information

Remarks

When you handle PointerWheelChanged, you are usually going to check the MouseWheelDelta property value:

1. Call GetCurrentPoint from the PointerRoutedEventArgs available to your handler. This returns a PointerPoint.
2. Get the Properties of the PointerPoint. It contains a PointerPointProperties object.
3. Get the MouseWheelDelta property value from the PointerPointProperties object.

If the element where pointer events occur has a non-default ManipulationMode value, then the action might also result in various manipulation events like ManipulationStarted. In addition, mouse wheel input can be handled as a built-in manipulation behavior by controls, even with no ManipulationMode value set. For example, certain controls like GridView and ListView can process mouse wheel input to initiate a scroll/pan action.

PointerWheelChanged is a routed event. For more info on the routed event concept, see Events and routed events overview.

For touch actions and also for interaction-specific or manipulation events that are consequences of a touch action, an element must be hit-test visible in order to be the event source and fire the event that is associated with the action. UIElement.Visibility must be Visible. Other properties of derived types also affect hit-test visibility. For more info, see Hit testing and input events.

PointerWheelChanged supports the ability to attach event handlers to the route that will be invoked even if the event data for the event is marked Handled. See AddHandler.

Specific Windows Runtime controls may have class-based handling for the PointerWheelChanged input event. If so, the control probably has an override for the method OnPointerWheelChanged. Typically the event is marked handled by the class handler, and the PointerWheelChanged event is not raised for handling by any user code handlers on that control. A control might do this in order to support traversal of its child elements by using a pointer wheel action. For more info on how class-based handling for events works, see Input event handlers in controls.

Requirements

See also

UIElement

Quickstart: touch input

Build date: 1/31/2013