# As<TDerived>()

> Converts this callback to a more constrained callback type.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine.UIElements](/engine/6000.6/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

## As\<T>()

```csharp
public EventCallbackDefinition<TDerived> As<TDerived>() where TDerived : TElement
```

### Returns

| Type                                                                                                             | Description                                                   |
| ---------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------- |
| [EventCallbackDefinition\<T>](/engine/6000.6/script-reference/unityengine/uielements/eventcallbackdefinition.md) | The same callback but with a more constrained type signature. |

### Remarks

This allows a callback declared for a base class to be used as part of a callback group alongside other callbacks from a derived class.