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# UILayoutSupport

A set of methods that provide layout support and access to layout anchors.

```
@MainActor protocol UILayoutSupport : NSObjectProtocol
```

## Overview

This protocol is implemented by the [`UIViewController`](/documentation/UIKit/UIViewController) properties [`topLayoutGuide`](/documentation/UIKit/UIViewController/topLayoutGuide) and [`bottomLayoutGuide`](/documentation/UIKit/UIViewController/bottomLayoutGuide) to support using Auto Layout with a view controller’s view. You can use layout guides as layout items in the [`NSLayoutConstraint`](/documentation/UIKit/NSLayoutConstraint) factory methods.

## Topics

### Creating constraints using layout anchors

[`bottomAnchor`](/documentation/UIKit/UILayoutSupport/bottomAnchor)

A layout anchor representing the guide’s bottom edge.

[`heightAnchor`](/documentation/UIKit/UILayoutSupport/heightAnchor)

A layout anchor representing the guide’s height.

[`topAnchor`](/documentation/UIKit/UILayoutSupport/topAnchor)

A layout anchor representing the guide’s top edge.

### Performing layout calculations

[`length`](/documentation/UIKit/UILayoutSupport/length)

Provides the length, in points, of the portion of a view controller’s view that is overlaid by translucent or transparent UIKit bars.

## Relationships

### Inherits From

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

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