---
title: CardSession.Event.readerDetected
framework: corenfc
role: symbol
role_heading: Case
path: corenfc/cardsession/event/readerdetected
---

# CardSession.Event.readerDetected

The session detected the RF field of an external NFC reader.

## Declaration

```swift
case readerDetected
```

## See Also

### Events

- [CardSession.Event.sessionStarted](corenfc/cardsession/event/sessionstarted.md)
- [CardSession.Event.received(_:)](corenfc/cardsession/event/received(_:).md)
- [CardSession.APDU](corenfc/cardsession/apdu.md)
- [CardSession.Event.readerDeselected](corenfc/cardsession/event/readerdeselected.md)
- [CardSession.Event.sessionInvalidated(reason:)](corenfc/cardsession/event/sessioninvalidated(reason:).md)