ApplicationStateObserver

The ApplicationStateObserver module defines an observer to listen for application state changes. It can be used as an input parameter in registerApplicationStateObserver to listen for lifecycle changes of the current application.

System capability: SystemCapability.Ability.AbilityRuntime.Core

System API: This is a system API and cannot be called by third-party applications.

Name		Type	Readable	Writable	Description
onForegroundApplicationChanged⁸⁺	AppStateData	AsyncCallback<void>	Yes	No	Callback invoked when the foreground or background state of an application changes.
onAbilityStateChanged⁸⁺	AbilityStateData	AsyncCallback<void>	Yes	No	Callback invoked when the ability state changes.
onProcessCreated⁸⁺	ProcessData	AsyncCallback<void>	Yes	No	Callback invoked when a process is created.
onProcessDied⁸⁺	ProcessData	AsyncCallback<void>	Yes	No	Callback invoked when a process is destroyed.
onProcessStateChanged⁸⁺	ProcessData	AsyncCallback<void>	Yes	No	Callback invoked when the process state is changed.

Example

import appManager from "@ohos.application.appManager";

let applicationStateObserver = {
    onForegroundApplicationChanged(appStateData) {
        console.log('onForegroundApplicationChanged appStateData: ' +  JSON.stringify(appStateData));
    },
    onAbilityStateChanged(abilityStateData) {
        console.log('onAbilityStateChanged onAbilityStateChanged: ' +  JSON.stringify(abilityStateData));
    },
    onProcessCreated(processData) {
        console.log('onProcessCreated onProcessCreated: '  +  JSON.stringify(processData));
    },
    onProcessDied(processData) {
        console.log('onProcessDied onProcessDied: '  +  JSON.stringify(processData));
    },
    onProcessStateChanged(processData) {
        console.log('onProcessStateChanged onProcessStateChanged: ' +  JSON.stringify(processData));
    }
};
let observerCode = appManager.registerApplicationStateObserver(applicationStateObserver);