@ohos.telephony.observer (Observer)

The observer module provides event subscription management functions. You can register or unregister an observer that listens for the following events: network status change, signal status change, call status change, cellular data connection status, uplink and downlink data flow status of cellular data services, and SIM status change.

NOTE

The initial APIs of this module are supported since API version 6. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import observer from '@ohos.telephony.observer';

observer.on('networkStateChange')

on(type: 'networkStateChange', callback: Callback<NetworkState>): void

Registers an observer for network status change events. This API uses an asynchronous callback to return the execution result.

Required permission: ohos.permission.GET_NETWORK_INFO

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

observer.on('networkStateChange', (data: observer.NetworkState) => {
    console.log("on networkStateChange, data:" + JSON.stringify(data));
});

observer.on('networkStateChange')

on(type: 'networkStateChange', options: { slotId: number }, callback: Callback<NetworkState>): void

Registers an observer for network status change events of the SIM card in the specified slot. This API uses an asynchronous callback to return the execution result.

Required permission: ohos.permission.GET_NETWORK_INFO

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('networkStateChange', id, (data: observer.NetworkState) => {
    console.log("on networkStateChange, data:" + JSON.stringify(data));
});

observer.off('networkStateChange')

off(type: 'networkStateChange', callback?: Callback<NetworkState>): void

Unregisters the observer for network status change events. This API uses an asynchronous callback to return the execution result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

let callback: (data: observer.NetworkState) => void = (data: observer.NetworkState) => {
    console.log("on networkStateChange, data:" + JSON.stringify(data));
}
observer.on('networkStateChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('networkStateChange', callback);
observer.off('networkStateChange');

observer.on('signalInfoChange')

on(type: 'signalInfoChange', callback: Callback<Array<SignalInformation>>): void

Registers an observer for signal status change events. This API uses an asynchronous callback to return the execution result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import radio from '@ohos.telephony.radio';

observer.on('signalInfoChange', (data: Array<radio.SignalInformation>) => {
    console.log("on signalInfoChange, data:" + JSON.stringify(data));
});

observer.on('signalInfoChange')

on(type: 'signalInfoChange', options: { slotId: number }, callback: Callback<Array<SignalInformation>>): void

Registers an observer for signal status change events of the SIM card in the specified slot. This API uses an asynchronous callback to return the execution result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import radio from '@ohos.telephony.radio';

class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('signalInfoChange', id, (data: Array<radio.SignalInformation>) => {
    console.log("on signalInfoChange, data:" + JSON.stringify(data));
});

observer.off('signalInfoChange')

off(type: 'signalInfoChange', callback?: Callback<Array<SignalInformation>>): void

Unregisters the observer for signal status change events. This API uses an asynchronous callback to return the execution result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import radio from '@ohos.telephony.radio';

let callback: (data: Array<radio.SignalInformation>) => void = (data: Array<radio.SignalInformation>) => {
    console.log("on signalInfoChange, data:" + JSON.stringify(data));
}
observer.on('signalInfoChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('signalInfoChange', callback);
observer.off('signalInfoChange');

observer.on('cellInfoChange')⁸⁺

on(type: 'cellInfoChange', callback: Callback<Array<CellInformation>>): void

Registers an observer for cell information change events. This API uses an asynchronous callback to return the result.

System API: This is a system API.

Required permissions: ohos.permission.LOCATION and ohos.permission.APPROXIMATELY_LOCATION

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import radio from '@ohos.telephony.radio';

observer.on('cellInfoChange', (data: Array<radio.CellInformation>) => {
    console.log("on cellInfoChange, data:" + JSON.stringify(data));
});

observer.on('cellInfoChange')⁸⁺

on(type: 'cellInfoChange', options: { slotId: number }, callback: Callback<Array<CellInformation>>): void

Registers an observer for signal status change events of the SIM card in the specified slot. This API uses an asynchronous callback to return the execution result.

System API: This is a system API.

Required permissions: ohos.permission.LOCATION and ohos.permission.APPROXIMATELY_LOCATION

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import radio from '@ohos.telephony.radio';

class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('cellInfoChange', id, (data: Array<radio.CellInformation>) => {
    console.log("on cellInfoChange, data:" + JSON.stringify(data));
});

observer.off('cellInfoChange')⁸⁺

off(type: 'cellInfoChange', callback?: Callback<Array<CellInformation>>): void

Unregisters the observer for cell information change events. This API uses an asynchronous callback to return the result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System API: This is a system API.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import radio from '@ohos.telephony.radio';

let callback: (data: Array<radio.CellInformation>) => void = (data: Array<radio.CellInformation>) => {
    console.log("on cellInfoChange, data:" + JSON.stringify(data));
}
observer.on('cellInfoChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('cellInfoChange', callback);
observer.off('cellInfoChange');

observer.on('callStateChange')

on(type: 'callStateChange', callback: Callback<{ state: CallState, number: string }>): void

Registers an observer for call status change events. This API uses an asynchronous callback to return the execution result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import call from '@ohos.telephony.call';

class Value {
    state: call.CallState = call.CallState.CALL_STATE_UNKNOWN
    number: string = ""
}
observer.on('callStateChange', (value: Value) => {
    console.log("on callStateChange, state:" + value.state + ", number:" + value.number);
});

observer.on('callStateChange')

on(type: 'callStateChange', options: { slotId: number }, callback: Callback<{ state:CallState, number: string }>): void

Registers an observer for call status change events. This API uses an asynchronous callback to return the execution result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import call from '@ohos.telephony.call';

class Value {
    state: call.CallState = call.CallState.CALL_STATE_UNKNOWN
    number: string = ""
}
class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('callStateChange', id, (value: Value) => {
    console.log("on callStateChange, state:" + value.state + ", number:" + value.number);
});

observer.off('callStateChange')

off(type: 'callStateChange', callback?: Callback<{ state: CallState, number: string }>): void

Unregisters the observer for call status change events. This API uses an asynchronous callback to return the execution result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import call from '@ohos.telephony.call';

class Value {
    state: call.CallState = call.CallState.CALL_STATE_UNKNOWN
    number: string = ""
}
let callback: (value: Value) => void = (value: Value) => {
    console.log("on callStateChange, state:" + value.state + ", number:" + value.number);
}
observer.on('callStateChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('callStateChange', callback);
observer.off('callStateChange');

observer.on('cellularDataConnectionStateChange')⁷⁺

on(type: 'cellularDataConnectionStateChange', callback: Callback<{ state: DataConnectState, network: RatType}>): void

Registers an observer for connection status change events of the cellular data link. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import data from '@ohos.telephony.data';
import radio from '@ohos.telephony.radio';

class Value {
    state: data.DataConnectState = data.DataConnectState.DATA_STATE_UNKNOWN
    network: radio.RadioTechnology = radio.RadioTechnology.RADIO_TECHNOLOGY_UNKNOWN
}
observer.on('cellularDataConnectionStateChange', (value: Value) => {
    console.log("on cellularDataConnectionStateChange, state:" + value.state + ", network:" + value.network);
});

observer.on('cellularDataConnectionStateChange')⁷⁺

on(type: 'cellularDataConnectionStateChange', options: { slotId: number }, callback: Callback<{ state: DataConnectState, network: RatType }>): void

Registers an observer for connection status change events of the cellular data link over the SIM card in the specified slot. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import data from '@ohos.telephony.data';
import radio from '@ohos.telephony.radio';

class Value {
    state: data.DataConnectState = data.DataConnectState.DATA_STATE_UNKNOWN
    network: radio.RadioTechnology = radio.RadioTechnology.RADIO_TECHNOLOGY_UNKNOWN
}
class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('cellularDataConnectionStateChange', id, (value: Value) => {
    console.log("on cellularDataConnectionStateChange, state:" + value.state + ", network:" + value.network);
});

observer.off('cellularDataConnectionStateChange')⁷⁺

off(type: 'cellularDataConnectionStateChange', callback?: Callback<{ state: DataConnectState, network: RatType}>): void

Unregisters the observer for connection status change events of the cellular data link. This API uses an asynchronous callback to return the result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import data from '@ohos.telephony.data';
import radio from '@ohos.telephony.radio';

class Value {
    state: data.DataConnectState = data.DataConnectState.DATA_STATE_UNKNOWN
    network: radio.RadioTechnology = radio.RadioTechnology.RADIO_TECHNOLOGY_UNKNOWN
}
let callback: (value: Value) => void = (value: Value) => {
    console.log("on cellularDataConnectionStateChange, state:" + value.state + ", network:" + value.network);
}
observer.on('cellularDataConnectionStateChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('cellularDataConnectionStateChange', callback);
observer.off('cellularDataConnectionStateChange');

observer.on('cellularDataFlowChange')⁷⁺

on(type: 'cellularDataFlowChange', callback: Callback<DataFlowType>): void

Registers an observer for the uplink and downlink data flow status change events of the cellular data service. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import data from '@ohos.telephony.data';

observer.on('cellularDataFlowChange', (data: data.DataFlowType) => {
    console.log("on cellularDataFlowChange, data:" + JSON.stringify(data));
});

observer.on('cellularDataFlowChange')⁷⁺

on(type: 'cellularDataFlowChange', options: { slotId: number }, callback: Callback<DataFlowType>): void

Registers an observer for the uplink and downlink data flow status change events of the cellular data service on the SIM card in the specified slot. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import data from '@ohos.telephony.data';

class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('cellularDataFlowChange', id, (data: data.DataFlowType) => {
    console.log("on cellularDataFlowChange, data:" + JSON.stringify(data));
});

observer.off('cellularDataFlowChange')⁷⁺

off(type: 'cellularDataFlowChange', callback?: Callback<DataFlowType>): void

Unregisters the observer for the uplink and downlink data flow status change events of the cellular data service. This API uses an asynchronous callback to return the result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

import data from '@ohos.telephony.data';

let callback: (data: data.DataFlowType) => void = (data: data.DataFlowType) => {
    console.log("on cellularDataFlowChange, data:" + JSON.stringify(data));
}
observer.on('cellularDataFlowChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('cellularDataFlowChange', callback);
observer.off('cellularDataFlowChange');

observer.on('simStateChange')⁷⁺

on(type: 'simStateChange', callback: Callback<SimStateData>): void

Registers an observer for SIM card status change events. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

observer.on('simStateChange', (data: observer.SimStateData) => {
    console.log("on simStateChange, data:" + JSON.stringify(data));
});

observer.on('simStateChange')⁷⁺

on(type: 'simStateChange', options: { slotId: number }, callback: Callback<SimStateData>): void

Registers an observer for status change events of the SIM card in the specified slot. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

class SlotId {
    slotId: number = 0
}
let id: SlotId = {slotId: 0}
observer.on('simStateChange', id, (data: observer.SimStateData) => {
    console.log("on simStateChange, data:" + JSON.stringify(data));
});

observer.off('simStateChange')⁷⁺

off(type: 'simStateChange', callback?: Callback<SimStateData>): void

Unregisters the observer for SIM card status change events. This API uses an asynchronous callback to return the result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

let callback: (data: observer.SimStateData) => void = (data: observer.SimStateData) => {
    console.log("on simStateChange, data:" + JSON.stringify(data));
}
observer.on('simStateChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('simStateChange', callback);
observer.off('simStateChange');

observer.on('iccAccountInfoChange')¹⁰⁺

on(type: 'iccAccountInfoChange', callback: Callback<void>): void

Registers an observer for account information change events of the SIM card. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

observer.on('iccAccountInfoChange', () => {
    console.log("on iccAccountInfoChange success");
});

observer.off('iccAccountInfoChange')¹⁰⁺

off(type: 'iccAccountInfoChange', callback?: Callback<void>): void

Unregisters the observer for account information change events of the SIM card. This API uses an asynchronous callback to return the result.

NOTE

You can pass the callback of the on function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.

System capability: SystemCapability.Telephony.StateRegistry

Parameters

Error codes

For details about the following error codes, see Telephony Error Codes.

Example

let callback: () => void = () => {
    console.log("on iccAccountInfoChange success");
}
observer.on('iccAccountInfoChange', callback);
// You can pass the callback of the on method to cancel listening for a certain type of callback. If you do not pass the callback, you will cancel listening for all callbacks.
observer.off('iccAccountInfoChange', callback);
observer.off('iccAccountInfoChange');

LockReason⁸⁺

Enumerates SIM card lock types.

System capability: SystemCapability.Telephony.StateRegistry

SimStateData⁷⁺

Enumerates SIM card types and states.

System capability: SystemCapability.Telephony.StateRegistry