Active Tag

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 method 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(result => {
      console.log("promise recv ndef response: " + result);
  });
  

connectedTag.readNdefTag

readNdefTag(callback: AsyncCallback<string>): void

Reads the content of this active tag. This method 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(result => {
      console.log("callback recv ndef response: " + result);
  });
  

connectedTag.writeNdefTag

writeNdefTag(data: string): Promise<void>

Writes data to this active tag. This method 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';
  
  writeNdefTag.write("010203")
      .then((value) => {
          // Data is written to the tag.
          console.log(`success to write event: ${value}`);
      }).catch((err) => {
          // Failed to write data to the tag.
          console.error(`failed to write event because ${err.code}`);
      });
  

connectedTag.writeNdefTag

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

Writes data to this active tag. This method 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.writeNdefTag("010203", (err, value) => {
      if (err) {
          // Failed to write data to the tag.
          console.error(`failed to write event because ${err.code}`);
          return;
      }
  
      // Data is written to the tag.
      console.log(`success to write event: ${value}`);
  });
  

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

• Enumerates the field strength states.

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';
  
  var NFC_RF_NOTIFY = "notify";
  
  var recvNfcRfNotifyFunc = result => {
      console.info("nfc rf receive state: " + result);
  }
  
  // Register event
  connectedTag.on(NFC_RF_NOTIFY, recvNfcRfNotifyFunc);
  
  // Unregister event
  connectedTag.off(NFC_RF_NOTIFY, recvNfcRfNotifyFunc);
  

NfcRfType

Enumerates the NFC states.