ApplicationStateObserver

The module defines an observer to listen for application state changes. It can be used as an input parameter in on('applicationState') to listen for lifecycle changes of the application.

NOTE

The initial APIs of this module are supported since API version 14. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import { appManager } from '@kit.AbilityKit';

ApplicationStateObserver.onForegroundApplicationChanged

onForegroundApplicationChanged(appStateData: AppStateData): void

Called when the foreground or background state of an application changes.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
appStateData AppStateData Yes Application state data.

ApplicationStateObserver.onAbilityStateChanged

onAbilityStateChanged(abilityStateData: AbilityStateData): void

Called when the ability state changes.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
abilityStateData AbilityStateData Yes Ability state data.

ApplicationStateObserver.onProcessCreated

onProcessCreated(processData: ProcessData): void

Called when a process is created.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
processData ProcessData Yes Process data.

ApplicationStateObserver.onProcessDied

onProcessDied(processData: ProcessData): void

Called when a process is destroyed.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
processData ProcessData Yes Process data.

ApplicationStateObserver.onProcessStateChanged

onProcessStateChanged(processData: ProcessData): void

Called when the process state is changed.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
processData ProcessData Yes Process data.

ApplicationStateObserver.onAppStarted

onAppStarted(appStateData: AppStateData): void

Called when the first process of the application is created.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
appStateData AppStateData Yes Application state data.

ApplicationStateObserver.onAppStopped

onAppStopped(appStateData: AppStateData): void

Called when the last process of the application is destroyed.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Name Type Mandatory Description
appStateData AppStateData Yes Application state data.

ProcessData

type ProcessData = _ProcessData.default

Defines the process data.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Type Description
_ProcessData.default Process data.

Example

import { appManager } from '@kit.AbilityKit';

let applicationStateObserver: appManager.ApplicationStateObserver = {
  onForegroundApplicationChanged(appStateData) {
    console.info(`onForegroundApplicationChanged, appStateData: ${JSON.stringify(appStateData)}.`);
  },
  onAbilityStateChanged(abilityStateData) {
    console.info(`onAbilityStateChanged, abilityStateData: ${JSON.stringify(abilityStateData)}.`);
  },
  onProcessCreated(processData) {
    console.info(`onProcessCreated, processData: ${JSON.stringify(processData)}.`);
  },
  onProcessDied(processData) {
    console.info(`onProcessDied, processData: ${JSON.stringify(processData)}.`);
  },
  onProcessStateChanged(processData) {
    console.info(`onProcessStateChanged, processData: ${JSON.stringify(processData)}.`);
  },
  onAppStarted(appStateData) {
    console.info(`onAppStarted, appStateData: ${JSON.stringify(appStateData)}.`);
  },
  onAppStopped(appStateData) {
    console.info(`onAppStopped, appStateData: ${JSON.stringify(appStateData)}.`);
  }
};
let observerCode = appManager.on('applicationState', applicationStateObserver);