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# primaryBackgroundStyle

The background style of the primary view controller.

```
var primaryBackgroundStyle: UISplitViewController.BackgroundStyle { get set }
```

## Discussion

In macOS, the sidebar of a split view has Liquid Glass behind its view. To achieve this effect in your iPad app when it runs in macOS, set [`primaryBackgroundStyle`](/documentation/UIKit/UISplitViewController/primaryBackgroundStyle) to [`UISplitViewController.BackgroundStyle.sidebar`](/documentation/UIKit/UISplitViewController/BackgroundStyle/sidebar). Set the style to [`UISplitViewController.BackgroundStyle.none`](/documentation/UIKit/UISplitViewController/BackgroundStyle/none) when you want to control the background appearance of the primary view controller.

> Note:
> Setting the background style to ``doc://com.apple.uikit/documentation/UIKit/UISplitViewController/BackgroundStyle/sidebar`` has no effect when your app is running in iOS or tvOS.

---

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