@ohos.connectedTag

The connectedTag module provides APIs for using active tags. You can use the APIs to initialize the active tag chip and read and write active tags.

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 connectedTag from '@ohos.connectedTag';

connectedTag.init

init(): boolean

Initializes the active tag chip.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Return value

connectedTag.uninit

uninit(): boolean

Uninitializes the active tag resources.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Return value

connectedTag.readNdefTag

readNdefTag(): Promise<string>

Reads the content of this active tag. This API uses a promise to return the result.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Return value

Example

import connectedTag from '@ohos.connectedTag';

connectedTag.readNdefTag().then((data) => {
    console.log("connectedTag readNdefTag Promise data = " + data);
}).catch((err)=> {
    console.log("connectedTag readNdefTag Promise err: " + err);
});

connectedTag.readNdefTag

readNdefTag(callback: AsyncCallback<string>): void

Reads the content of this active tag. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Parameters

Example

import connectedTag from '@ohos.connectedTag';

connectedTag.readNdefTag((err, data)=> {
    if (err) {
        console.log("connectedTag readNdefTag AsyncCallback err: " + err);
    } else {
        console.log("connectedTag readNdefTag AsyncCallback data: " + data);
    }
});

connectedTag.writeNdefTag

writeNdefTag(data: string): Promise<void>

Writes data to this active tag. This API uses a promise to return the result.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Parameters

Return value

Example

import connectedTag from '@ohos.connectedTag';

var rawData = "010203"; // change it tobe correct.
connectedTag.writeNdefTag(rawData).then(() => {
    console.log("connectedTag writeNdefTag Promise success.");
}).catch((err)=> {
    console.log("connectedTag writeNdefTag Promise err: " + err);
});

connectedTag.writeNdefTag

writeNdefTag(data: string, callback: AsyncCallback<void>): void

Writes data to this active tag. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Parameters

Example

import connectedTag from '@ohos.connectedTag';

var rawData = "010203"; // change it tobe correct.
connectedTag.writeNdefTag(rawData, (err)=> {
    if (err) {
        console.log("connectedTag writeNdefTag AsyncCallback err: " + err);
    } else {
        console.log("connectedTag writeNdefTag AsyncCallback success.");
    }
});

connectedTag.on('notify')

on(type: "notify", callback: Callback<number>): void

Registers the NFC field strength state events.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Parameters

connectedTag.off('notify')

off(type: "notify", callback?: Callback<number>): void

Unregisters the NFC field strength state events.

Required permissions: ohos.permission.NFC_TAG

System capability: SystemCapability.Communication.ConnectedTag

Parameters

Example

import connectedTag from '@ohos.connectedTag';

// Register the event.
connectedTag.on("notify", (err, rfState)=> {
    if (err) {
        console.log("connectedTag on Callback err: " + err);
    } else {
        console.log("connectedTag on Callback rfState: " + rfState);
    }
});

var initStatus = connectedTag.init();
console.log("connectedTag init status: " + initStatus);

// Add nfc connecected tag business oprations here...
// connectedTag.writeNdefTag(rawData)
// connectedTag.readNdefTag()

var uninitStatus = connectedTag.uninit();
console.log("connectedTag uninit status: " + uninitStatus);

// Unregister the event.
connectedTag.off("notify", (err, rfState)=> {
    if (err) {
        console.log("connectedTag off Callback err: " + err);
    } else {
        console.log("connectedTag off Callback rfState: " + rfState);
    }
});

NfcRfType

Enumerates the NFC field strength states.

System capability: SystemCapability.Communication.ConnectedTag