NfcV

Kotlin |Java

class NfcV : TagTechnology

kotlin.Any
↳	android.nfc.tech.NfcV

Provides access to NFC-V (ISO 15693) properties and I/O operations on a Tag.

Acquire a NfcV object using get.

The primary NFC-V I/O operation is transceive. Applications must implement their own protocol stack on top of transceive.

Note: Methods that perform I/O operations require the android.Manifest.permission#NFC permission.

Summary

Public methods
Unit	`close()`
Unit	`connect()`
static NfcV!	`get(tag: Tag!)` Get an instance of `NfcV` for the given tag.
Byte	`getDsfId()` Return the DSF ID bytes from tag discovery.
Int	`getMaxTransceiveLength()` Return the maximum number of bytes that can be sent with `transceive`.
Byte	`getResponseFlags()` Return the Response Flag bytes from tag discovery.
Tag!	`getTag()`
Boolean	`isConnected()`
ByteArray!	`transceive(data: ByteArray!)` Send raw NFC-V commands to the tag and receive the response.

Public methods

close

Added in API level 10

fun close(): Unit

Exceptions
`java.lang.Exception`	if this resource cannot be closed
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	if the tag object is reused after the tag has left the field

connect

Added in API level 10

fun connect(): Unit

Exceptions
`TagLostException`	if the tag leaves the field
`java.io.IOException`	if there is an I/O failure, or connect is canceled
`java.lang.SecurityException`	if the tag object is reused after the tag has left the field

get

Added in API level 10

static fun get(tag: Tag!): NfcV!

Get an instance of NfcV for the given tag.

Returns null if NfcV was not enumerated in Tag.getTechList. This indicates the tag does not support NFC-V.

Does not cause any RF activity and does not block.

Parameters
`tag`	Tag!: an NFC-V compatible tag

Return
`NfcV!`	NFC-V object

getDsfId

Added in API level 10

fun getDsfId(): Byte

Return the DSF ID bytes from tag discovery.

Does not cause any RF activity and does not block.

Return
`Byte`	DSF ID bytes

getMaxTransceiveLength

Added in API level 14

fun getMaxTransceiveLength(): Int

Return the maximum number of bytes that can be sent with transceive.

Return
`Int`	the maximum number of bytes that can be sent with `transceive`.

getResponseFlags

Added in API level 10

fun getResponseFlags(): Byte

Return the Response Flag bytes from tag discovery.

Does not cause any RF activity and does not block.

Return
`Byte`	Response Flag bytes

getTag

Added in API level 10

fun getTag(): Tag!

Return
`Tag!`	the `Tag` backing this `TagTechnology` object.

isConnected

Added in API level 10

fun isConnected(): Boolean

Return
`Boolean`	true if I/O operations should be possible

transceive

Added in API level 10

fun transceive(data: ByteArray!): ByteArray!

Send raw NFC-V commands to the tag and receive the response.

Applications must not append the CRC to the payload, it will be automatically calculated. The application does provide FLAGS, CMD and PARAMETER bytes.

Use getMaxTransceiveLength to retrieve the maximum amount of bytes that can be sent with transceive.

This is an I/O operation and will block until complete. It must not be called from the main application thread. A blocked call will be canceled with IOException if #close is called from another thread.

Requires the android.Manifest.permission#NFC permission.

Parameters
`data`	ByteArray!: bytes to send

Return
`ByteArray!`	bytes received in response

Exceptions
`TagLostException`	if the tag leaves the field
`java.io.IOException`	if there is an I/O failure, or this operation is canceled