# GH_Canvas.CanvasPrePaintWidgetsEventHandler delegate

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

```cs
public delegate GH_Canvas.CanvasPrePaintWidgetsEventHandler
```

**Signature:**

```cs
void GH_Canvas.CanvasPrePaintWidgetsEventHandler(GH_Canvas sender)
```

**Parameters:**

- `sender` ([GH_Canvas](https://developer.rhino3d.com/api/gh1/type/grasshopper.gui.canvas.gh-canvas.md))