# GH_VerticalScrollBar.ScrollRatioChangedEventHandler 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_VerticalScrollBar.ScrollRatioChangedEventHandler
```

**Signature:**

```cs
void GH_VerticalScrollBar.ScrollRatioChangedEventHandler(GH_VerticalScrollBar sender, double ratio)
```

**Parameters:**

- `sender` ([GH_VerticalScrollBar](https://developer.rhino3d.com/api/gh1/type/grasshopper.gui.gh-verticalscrollbar.md))
- `ratio` ([double](https://learn.microsoft.com/dotnet/api/system.double))