AppForegroundStateObserver (System API)

The module defines the listener used to listen for application startup and exit state changes. It can be used as an input parameter of appManager.on('appForegroundState') to listen for the state changes of all applications.

NOTE

The initial APIs of this module are supported since API version 11. Newly added APIs will be marked with a superscript to indicate their earliest API version. The APIs provided by this module are system APIs.

Modules to Import

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

AppForegroundStateObserver

onAppStateChanged

onAppStateChanged(appStateData: AppStateData): void

Called when the application launch or exit state changes.

System capability: SystemCapability.Ability.AbilityRuntime.Core

System API: This is a system API.

Parameters

Name	Type	Mandatory	Description
appStateData	AppStateData	Yes	Application state data.

Example

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

let observer: appManager.AppForegroundStateObserver = {
  onAppStateChanged(appStateData: appManager.AppStateData) {
    console.info(`onAppStateChanged appStateData: ${JSON.stringify(appStateData)}`);
  },
};
appManager.on('appForegroundState', observer);