A unique identifier for this photo settings instance.
- iOS 10.0+
- macOS 10.15+
- Mac Catalyst 13.0+
AVCapture instance automatically assigns a unique value to this property.
Use this property to track a photo capture request. After you call the
capture method, the photo capture output calls your delegate object to provide information about the progress and results of the capture. Each delegate method includes a
unique property matches the
unique value of the
AVCapture object you used to request capture.
It is illegal to reuse a
AVCapture instance for multiple captures. Calling the
capture method throws an exception (
invalid) if the
unique value matches that of any previously used settings object.