harmony 鸿蒙@ohos.nfc.controller (Standard NFC)

2022-08-09
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@ohos.nfc.controller (Standard NFC)

The nfcController module provides APIs for opening and closing Near-Field Communication (NFC) and reading the NFC state.

NOTE

The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import controller from '@ohos.nfc.controller';

NfcState

Enumerates the NFC states.

System capability: SystemCapability.Communication.NFC.Core

Name	Value	Description
STATE_OFF	1	NFC is closed (OFF).
STATE_TURNING_ON	2	NFC is turning on.
STATE_ON	3	NFC is open (ON).
STATE_TURNING_OFF	4	NFC is turning off.

controller.isNfcAvailable

isNfcAvailable(): boolean

Checks whether the device supports NFC.

NOTE

This API is supported since API version 7 and deprecated since API version 9. You are advised to use canIUse(“SystemCapability.Communication.NFC.Core”).

System capability: SystemCapability.Communication.NFC.Core

Return value

Type	Description
boolean	Returns true if the device supports NFC; returns false otherwise.

controller.openNfc

openNfc(): boolean

Opens NFC.

NOTE

This API is supported since API version 7 and deprecated since API version 9. You are advised to use enableNfc.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS

System capability: SystemCapability.Communication.NFC.Core

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

controller.enableNfc⁹⁺

enableNfc(): void

Enables NFC.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS

System capability: SystemCapability.Communication.NFC.Core

Error codes

For details about the error codes, see NFC Error Codes.

ID	Error Message
3100101	NFC state is abnormal in service.

controller.closeNfc

closeNfc(): boolean

Closes NFC.

NOTE

This API is supported since API version 7 and deprecated since API version 9. You are advised to use disableNfc.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS

System capability: SystemCapability.Communication.NFC.Core

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

controller.disableNfc⁹⁺

disableNfc(): void

Disables NFC.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS

System capability: SystemCapability.Communication.NFC.Core

Error codes

For details about the error codes, see NFC Error Codes.

ID	Error Message
3100101	NFC state is abnormal in service.

controller.isNfcOpen

isNfcOpen(): boolean

Checks whether NFC is open.

System capability: SystemCapability.Communication.NFC.Core

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.Core

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. A callback will be invoked to return the NFC state when the NFC state changes.

System capability: SystemCapability.Communication.NFC.Core

Parameters

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.

controller.off(‘nfcStateChange’)

off(type: “nfcStateChange”, callback?: Callback<NfcState>): void

Unsubscribes from the NFC state changes. The subscriber will not receive NFC state change notifications.

System capability: SystemCapability.Communication.NFC.Core

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type to unsubscribe from. The value is nfcStateChange.
callback	Callback<NfcState>	No	Callback for the NFC state changes. This parameter can be left blank. If this parameter is not specified, all callbacks associated with the specified event will be unregistered.

Example

import controller from '@ohos.nfc.controller';

// Register a callback to receive the NFC state change notification.
controller.on("nfcStateChange", (nfcState : number)=> {
  console.log("controller on callback nfcState: " + nfcState);
});

// Open NFC. The ohos.permission.MANAGE_SECURE_SETTINGS permission is required.
if (!controller.isNfcOpen()) {
  let ret = controller.openNfc();
  console.log("controller openNfc ret: " + ret);
}

// Use 'enableNfc' to enable NFC from API version 9.
try {
  controller.enableNfc();
  console.log("controller enableNfc success");
} catch (busiError) {
  console.log("controller enableNfc busiError: " + busiError);
}

// Close NFC. The ohos.permission.MANAGE_SECURE_SETTINGS permission is required.
if (controller.isNfcOpen()) {
  let ret = controller.closeNfc();
  console.log("controller closeNfc ret: " + ret);
}

// Use 'disableNfc' to disable NFC from API version 9.
try {
  controller.disableNfc();
  console.log("controller disableNfc success");
} catch (busiError) {
  console.log("controller disableNfc busiError: " + busiError);
}

// Unregister the callback.
controller.off("nfcStateChange");