@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. |
Example
import controller from '@ohos.nfc.controller';
// Register a callback to receive the NFC state change notification.
controller.on("nfcStateChange", (err, nfcState)=> {
if (err) {
console.log("controller on callback err: " + err);
} else {
console.log("controller on callback nfcState: " + nfcState);
}
});
// Open NFC. The ohos.permission.MANAGE_SECURE_SETTINGS permission is required.
if (!controller.isNfcOpen()) {
var 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()) {
var 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");