Standard NFC
Implements Near-Field Communication (NFC).
NOTE
The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
Modules to Import
import controller from '@ohos.nfc.controller';
controller.isNfcAvailable
isNfcAvailable(): boolean
Checks whether NFC is available.
Return value
| Type | Description |
|---|---|
| boolean | Returns true if NFC is available; returns false otherwise. |
controller.openNfc
openNfc(): boolean
Opens NFC.
Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS
System capability: SystemCapability.Communication.NFC
Return value
| Type | Description |
|---|---|
| boolean | Returns true if the operation is successful; returns false otherwise. |
controller.closeNfc
closeNfc(): boolean
Closes NFC.
Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS
System capability: SystemCapability.Communication.NFC
Return value
| Type | Description |
|---|---|
| boolean | Returns true if the operation is successful; returns false otherwise. |
controller.isNfcOpen
isNfcOpen(): boolean
Checks whether NFC is open.
System capability: SystemCapability.Communication.NFC
Return value
| Type | Description |
|---|---|
| boolean | Returns true if NFC is open; returns false otherwise. |
controller.getNfcState
getNfcState(): NfcState
Obtains the NFC state.
System capability: SystemCapability.Communication.NFC
Return value
| Type | Description |
|---|---|
| NfcState | NFC state obtained. For details, see NfcState. |
controller.on('nfcStateChange')
on(type: "nfcStateChange", callback: Callback<NfcState>): void
Subscribes to NFC state changes.
System capability: SystemCapability.Communication.NFC
Parameter
| Name | Type | Mandatory | Description |
|---|---|---|---|
| type | string | Yes | Event type to subscribe to. The value is nfcStateChange. |
| callback | Callback<NfcState> | Yes | Callback invoked to return the NFC state changes. |
controller.off('nfcStateChange')
off(type: "nfcStateChange", callback?: Callback<NfcState>): void
Unsubscribes from the NFC state changes.
System capability: SystemCapability.Communication.NFC
Parameter
| Name | Type | Mandatory | Description |
|---|---|---|---|
| type | string | Yes | Event type to unsubscribe from. The value is nfcStateChange. |
| callback | Callback<NfcState> | No | Callback used to return the NFC state changes. If this parameter is not specified, all callbacks associated with the specified event will be unregistered. |
Example
import nfcController from '@ohos.nfcController';
var NFC_STATE_NOTIFY = "nfcStateChange";
var recvNfcStateNotifyFunc = result => {
console.info("nfc state receive state: " + result);
}
// Subscribe to the NFC state changes.
nfcController.on(NFC_STATE_NOTIFY, recvNfcStateNotifyFunc);
// Unsubscribe from the NFC state changes.
nfcController.off(NFC_STATE_NOTIFY, recvNfcStateNotifyFunc);
NfcState
Enumerates the NFC states.
| Name | Default Value | Description |
|---|---|---|
| STATE_OFF | 1 | Off |
| STATE_TURNING_ON | 2 | Turning on |
| STATE_ON | 3 | On |
| STATE_TURNING_OFF | 4 | Turning off |