# Sandbox.UI.PanelRenderTreeBuilder.AddAttributeString

```csharp
void AddAttributeString(int sequence, string attrName, string value)
```

Handles "style" and "class" attributes..

### Parameters

- `sequence` (`int`)
- `attrName` (`string`)
- `value` (`string`)

Declared in [Sandbox.UI.PanelRenderTreeBuilder](/api/Sandbox.UI.PanelRenderTreeBuilder).
Assembly: `Sandbox.Engine`.