# WheelEvent

> This event is sent when the mouse wheel moves.

## Definition

* **Type:** Class
* **Namespace:** [UnityEngine.UIElements](/engine/6000.5/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule
* **Inherits from:** [MouseEventBase\<WheelEvent>](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1.md)
* **Implements:** [IDisposable](https://learn.microsoft.com/dotnet/api/system.idisposable), [IMouseEvent](/engine/6000.5/script-reference/unityengine/uielements/imouseevent.md)

```csharp
public class WheelEvent : MouseEventBase<WheelEvent>, IDisposable, IMouseEvent
```

## Remarks

The mouse wheel event is sent to the visual element under the mouse when the mouse scroll wheel value changes. A WheelEvent uses the default mouse event propagation path: it trickles down, bubbles up and can be cancelled. Disabled elements won't receive this event by default.

## Static Fields

| Value                                                                                                         | Description                                                                                 |
| ------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- |
| [scrollDeltaPerTick](/engine/6000.5/script-reference/unityengine/uielements/wheelevent/scrolldeltapertick.md) | The magnitude of WheelEvent.delta that corresponds to exactly one tick of the scroll wheel. |

## Constructors

| Constructor                                                                               | Description                                                                  |
| ----------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------- |
| [WheelEvent()](/engine/6000.5/script-reference/unityengine/uielements/wheelevent/ctor.md) | Constructor. Use GetPooled() to get an event from a pool of reusable events. |

## Properties

| Property                                                                            | Description                                           |
| ----------------------------------------------------------------------------------- | ----------------------------------------------------- |
| [delta](/engine/6000.5/script-reference/unityengine/uielements/wheelevent/delta.md) | The amount of scrolling applied with the mouse wheel. |

## Methods

| Method                                                                            | Description                                       |
| --------------------------------------------------------------------------------- | ------------------------------------------------- |
| [Init](/engine/6000.5/script-reference/unityengine/uielements/wheelevent/init.md) | Resets the event members to their initial values. |

## Static Methods

| Method                                                                                      | Description                                                                                                                                                                                                                                    |
| ------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [GetPooled](/engine/6000.5/script-reference/unityengine/uielements/wheelevent/getpooled.md) | Gets an event from the event pool and initializes it with the given values. Use this function instead of creating new events. Events obtained using this method need to be released back to the pool. You can use `Dispose()` to release them. |

## Inheritance

**Inherited Members:**

* MouseEventBase\<WheelEvent>.PreDispatch(IPanel)
* MouseEventBase\<WheelEvent>.PostDispatch(IPanel)
* [MouseEventBase\<WheelEvent>.GetPooled(Vector2, int, int, Vector2, EventModifiers)](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/getpooled.md)
* [MouseEventBase\<WheelEvent>.GetPooled(IMouseEvent)](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/getpooled.md)
* [MouseEventBase\<WheelEvent>.GetPooled(IPointerEvent)](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/getpooled.md)
* [MouseEventBase\<WheelEvent>.modifiers](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/modifiers.md)
* [MouseEventBase\<WheelEvent>.mousePosition](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/mouseposition.md)
* [MouseEventBase\<WheelEvent>.localMousePosition](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/localmouseposition.md)
* [MouseEventBase\<WheelEvent>.mouseDelta](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/mousedelta.md)
* [MouseEventBase\<WheelEvent>.clickCount](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/clickcount.md)
* [MouseEventBase\<WheelEvent>.button](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/button.md)
* [MouseEventBase\<WheelEvent>.pressedButtons](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/pressedbuttons.md)
* [MouseEventBase\<WheelEvent>.shiftKey](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/shiftkey.md)
* [MouseEventBase\<WheelEvent>.ctrlKey](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/ctrlkey.md)
* [MouseEventBase\<WheelEvent>.commandKey](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/commandkey.md)
* [MouseEventBase\<WheelEvent>.altKey](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/altkey.md)
* [MouseEventBase\<WheelEvent>.actionKey](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/actionkey.md)
* [MouseEventBase\<WheelEvent>.currentTarget](/engine/6000.5/script-reference/unityengine/uielements/mouseeventbase1/currenttarget.md)
* [EventBase\<WheelEvent>.SetCreateFunction(Func\<WheelEvent>)](/engine/6000.5/script-reference/unityengine/uielements/eventbase1/setcreatefunction.md)
* [EventBase\<WheelEvent>.TypeId()](/engine/6000.5/script-reference/unityengine/uielements/eventbase1/typeid.md)
* [EventBase\<WheelEvent>.GetPooled()](/engine/6000.5/script-reference/unityengine/uielements/eventbase1/getpooled.md)
* [EventBase\<WheelEvent>.Dispose()](/engine/6000.5/script-reference/unityengine/uielements/eventbase1/dispose.md)
* [EventBase\<WheelEvent>.eventTypeId](/engine/6000.5/script-reference/unityengine/uielements/eventbase1/eventtypeid.md)
* [EventBase.RegisterEventType()](/engine/6000.5/script-reference/unityengine/uielements/eventbase/registereventtype.md)
* [EventBase.StopPropagation()](/engine/6000.5/script-reference/unityengine/uielements/eventbase/stoppropagation.md)
* [EventBase.StopImmediatePropagation()](/engine/6000.5/script-reference/unityengine/uielements/eventbase/stopimmediatepropagation.md)
* [EventBase.timestamp](/engine/6000.5/script-reference/unityengine/uielements/eventbase/timestamp.md)
* [EventBase.bubbles](/engine/6000.5/script-reference/unityengine/uielements/eventbase/bubbles.md)
* [EventBase.tricklesDown](/engine/6000.5/script-reference/unityengine/uielements/eventbase/tricklesdown.md)
* [EventBase.ignoreDisabledElements](/engine/6000.5/script-reference/unityengine/uielements/eventbase/ignoredisabledelements.md)
* [EventBase.target](/engine/6000.5/script-reference/unityengine/uielements/eventbase/target.md)
* [EventBase.isPropagationStopped](/engine/6000.5/script-reference/unityengine/uielements/eventbase/ispropagationstopped.md)
* [EventBase.isImmediatePropagationStopped](/engine/6000.5/script-reference/unityengine/uielements/eventbase/isimmediatepropagationstopped.md)
* [EventBase.propagationPhase](/engine/6000.5/script-reference/unityengine/uielements/eventbase/propagationphase.md)
* [EventBase.dispatch](/engine/6000.5/script-reference/unityengine/uielements/eventbase/dispatch.md)
* [EventBase.imguiEvent](/engine/6000.5/script-reference/unityengine/uielements/eventbase/imguievent.md)
* [EventBase.originalMousePosition](/engine/6000.5/script-reference/unityengine/uielements/eventbase/originalmouseposition.md)
* [EventBase.pooled](/engine/6000.5/script-reference/unityengine/uielements/eventbase/pooled.md)