# RegisterCallbackAttribute(Type, CallbackOptions)

> Initializes a new instance of the RegisterCallbackAttribute class.

## Definition

* **Type:** Constructor
* **Namespace:** [UnityEngine.UIElements](/engine/6000.7/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
public RegisterCallbackAttribute(Type eventType, CallbackOptions callbackOptions = CallbackOptions.Default)
```

### Parameters

**** (\[Type]\(https\://learn.microsoft.com/dotnet/api/system.type)): Type of event to handle, for example `typeof(PointerDownEvent)`.**** (\[CallbackOptions]\(/engine/6000.7/script-reference/unityengine/uielements/callbackoptions)): Options that control how the callback is registered.