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# activePrimaryConstituentDeviceSwitchingBehavior

The switching behavior of the active constituent device.

```
var activePrimaryConstituentDeviceSwitchingBehavior: AVCaptureDevice.PrimaryConstituentDeviceSwitchingBehavior { get }
```

## Discussion

For virtual devices with multiple constituent devices, this property provides the active switching behavior. It equals the value of the [`primaryConstituentDeviceSwitchingBehavior`](/documentation/AVFoundation/AVCaptureDevice/primaryConstituentDeviceSwitchingBehavior-swift.property) property except when you record with an [`AVCaptureMovieFileOutput`](/documentation/AVFoundation/AVCaptureMovieFileOutput) that you configure to use different behavior.

The value of this property is [`AVCaptureDevice.PrimaryConstituentDeviceSwitchingBehavior.unsupported`](/documentation/AVFoundation/AVCaptureDevice/PrimaryConstituentDeviceSwitchingBehavior-swift.enum/unsupported) for devices that don’t support constituent device switching.

This property is key-value observable.

---

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