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# AUViewController

The base class to extend when creating a custom user interface for an audio unit.

```
class AUViewController
```

## Overview

This class doesn’t add any new methods or properties to its superclass, but it does conform to the <doc://com.apple.documentation/documentation/Foundation/NSExtensionRequestHandling> protocol.

A host app can access the view controller by calling the <doc://com.apple.documentation/documentation/AudioToolbox/AUAudioUnit/requestViewController(completionHandler:)> method on the corresponding <doc://com.apple.documentation/documentation/AudioToolbox/AUAudioUnit> object.

### Subclassing Notes

If an audio unit provides a custom view controller, the UI Audio Unit extension must implement a subclass of `AUViewController` and implement the <doc://com.apple.documentation/documentation/AudioToolbox/AUAudioUnitFactory> protocol inside the subclass.

## Relationships

### Conforms To

[`UIUserActivityRestoring`](/documentation/UIKit/UIUserActivityRestoring)

[`NSExtensionRequestHandling`](/documentation/Foundation/NSExtensionRequestHandling)

[`NSUserActivityRestoring`](/documentation/AppKit/NSUserActivityRestoring)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`UIContentContainer`](/documentation/UIKit/UIContentContainer)

[`NSEditor`](/documentation/AppKit/NSEditor)

[`UIStateRestoring`](/documentation/UIKit/UIStateRestoring)

[`NSSeguePerforming`](/documentation/AppKit/NSSeguePerforming)

[`Hashable`](/documentation/Swift/Hashable)

[`CVarArg`](/documentation/Swift/CVarArg)

[`NSStandardKeyBindingResponding`](/documentation/AppKit/NSStandardKeyBindingResponding)

[`UIResponderStandardEditActions`](/documentation/UIKit/UIResponderStandardEditActions)

[`UIPasteConfigurationSupporting`](/documentation/UIKit/UIPasteConfigurationSupporting)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`UIAppearanceContainer`](/documentation/UIKit/UIAppearanceContainer)

[`UITraitChangeObservable-67e94`](/documentation/UIKit/UITraitChangeObservable-67e94)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`UIFocusEnvironment`](/documentation/UIKit/UIFocusEnvironment)

[`UIActivityItemsConfigurationProviding`](/documentation/UIKit/UIActivityItemsConfigurationProviding)

[`UITraitEnvironment`](/documentation/UIKit/UITraitEnvironment)

[`NSTouchBarProvider`](/documentation/AppKit/NSTouchBarProvider)

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

[`NSCoding`](/documentation/Foundation/NSCoding)

[`Sendable`](/documentation/Swift/Sendable)

[`Equatable`](/documentation/Swift/Equatable)

[`NSUserInterfaceItemIdentification`](/documentation/AppKit/NSUserInterfaceItemIdentification)

### Inherits From

[`UIViewController`](/documentation/UIKit/UIViewController)

[`NSViewController`](/documentation/AppKit/NSViewController)

---

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