Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

# NfcAdapter.ReaderCallback

*** ** * ** ***


`
public
static


interface
NfcAdapter.ReaderCallback
`


`


`

|---|
| android.nfc.NfcAdapter.ReaderCallback |

<br />

*** ** * ** ***

A callback to be invoked when the system finds a tag while the foreground activity is
operating in reader mode.

Register your `ReaderCallback` implementation with `https://developer.android.com/reference/android/nfc/NfcAdapter#enableReaderMode(android.app.Activity,%20android.nfc.NfcAdapter.ReaderCallback,%20int,%20android.os.Bundle)` and disable it with `https://developer.android.com/reference/android/nfc/NfcAdapter#disableReaderMode(android.app.Activity)`.
**See also:**

- `https://developer.android.com/reference/android/nfc/NfcAdapter#enableReaderMode(android.app.Activity,%20android.nfc.NfcAdapter.ReaderCallback,%20int,%20android.os.Bundle)`

## Summary

| ### Public methods ||
|---|---|
| ` abstract void` | ` https://developer.android.com/reference/android/nfc/NfcAdapter.ReaderCallback#onTagDiscovered(android.nfc.Tag)(https://developer.android.com/reference/android/nfc/Tag tag) ` |
| ` default void` | ` https://developer.android.com/reference/android/nfc/NfcAdapter.ReaderCallback#onTagLost(android.nfc.Tag)(https://developer.android.com/reference/android/nfc/Tag tag) ` Called when the previously discovered tag is lost. |

## Public methods

### onTagDiscovered

Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public abstract void onTagDiscovered (Tag tag)
```

<br />

<br />

| Parameters ||
|---|---|
| `tag` | `Tag` <br /> |

### onTagLost

Added in [API level 37](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void onTagLost (Tag tag)
```

Called when the previously discovered tag is lost.

<br />

| Parameters ||
|---|---|
| `tag` | `Tag`: This value cannot be `null`. <br /> |