# GH_ListScroller.SelectedIndexChangedEventHandler delegate

Namespace: [Grasshopper.GUI](https://developer.rhino3d.com/api/gh1/namespace/grasshopper.gui.md) · Assembly: [Grasshopper](https://developer.rhino3d.com/api/gh1/assembly/grasshopper.md)

```cs
public delegate GH_ListScroller.SelectedIndexChangedEventHandler
```

**Signature:**

```cs
void GH_ListScroller.SelectedIndexChangedEventHandler(GH_ListScroller sender, GH_ListScrollerChangedEventArgs e)
```

**Parameters:**

- `sender` ([GH_ListScroller](https://developer.rhino3d.com/api/gh1/type/grasshopper.gui.gh-listscroller.md))
- `e` ([GH_ListScrollerChangedEventArgs](https://developer.rhino3d.com/api/gh1/type/grasshopper.gui.gh-listscrollerchangedeventargs.md))