# TreeViewExpansionChangedArgs

> A data structure for the tree view item expansion event.

## Definition

* **Type:** Class
* **Namespace:** [UnityEngine.UIElements](/engine/6000.5/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
public class TreeViewExpansionChangedArgs
```

## Properties

| Property                                                                                                                                | Description                                                                                                   |
| --------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------- |
| [id](/engine/6000.5/script-reference/unityengine/uielements/treeviewexpansionchangedargs/id.md)                                         | The id of the item being expanded or collapsed. Returns -1 when expandAll() or collapseAll() is being called. |
| [isAppliedToAllChildren](/engine/6000.5/script-reference/unityengine/uielements/treeviewexpansionchangedargs/isappliedtoallchildren.md) | Indicates whether the expandAllChildren or collapsedAllChildren is applied when expanding the item.           |
| [isExpanded](/engine/6000.5/script-reference/unityengine/uielements/treeviewexpansionchangedargs/isexpanded.md)                         | Indicates whether the item is expanded (true) or collapsed (false).                                           |