# UnbindHeader

> Callback triggered when the header is about to be destroyed or after domain reload.

## Definition

* **Type:** Field
* **Namespace:** [Unity.Hierarchy](/engine/6000.7/script-reference/unity/hierarchy.md)
* **Assembly:** UnityEngine.HierarchyModule

```csharp
public Action<VisualElement, HierarchyView> UnbindHeader
```