# @ohos.application.AbilityLifecycleCallback (AbilityLifecycleCallback)

The **AbilityLifecycleCallback** module provides callbacks, such as **onAbilityCreate**, **onWindowStageCreate**, and **onWindowStageDestroy**, to receive lifecycle state changes in the application context. These callbacks can be used as an input parameter of [registerAbilityLifecycleCallback](js-apis-inner-application-applicationContext.md#applicationcontextregisterabilitylifecyclecallback).

> **NOTE**
> 
> The APIs of this module are supported since API version 9 and are deprecated in versions later than API version 9. You are advised to use [@ohos.app.ability.AbilityLifecycleCallback](js-apis-app-ability-abilityLifecycleCallback.md) instead. Newly added APIs will be marked with a superscript to indicate their earliest API version. 
> The APIs of this module can be used only in the stage model.


## Modules to Import

```ts
import AbilityLifecycleCallback from "@ohos.application.AbilityLifecycleCallback";
```


## AbilityLifecycleCallback.onAbilityCreate

onAbilityCreate(ability: Ability): void;

Called when an ability is created.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|


## AbilityLifecycleCallback.onWindowStageCreate

onWindowStageCreate(ability: Ability, windowStage: window.WindowStage): void;

Called when the window stage of an ability is created.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|
| windowStage | [window.WindowStage](js-apis-window.md#windowstage9) | Yes| **WindowStage** object.|


## AbilityLifecycleCallback.onWindowStageActive

onWindowStageActive(ability: Ability, windowStage: window.WindowStage): void;

Called when the window stage of an ability gains focus.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|
| windowStage | [window.WindowStage](js-apis-window.md#windowstage9) | Yes| **WindowStage** object.|


## AbilityLifecycleCallback.onWindowStageInactive

onWindowStageInactive(ability: Ability, windowStage: window.WindowStage): void;

Called when the window stage of an ability loses focus.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|
| windowStage | [window.WindowStage](js-apis-window.md#windowstage9) | Yes| **WindowStage** object.|


## AbilityLifecycleCallback.onWindowStageDestroy

onWindowStageDestroy(ability: Ability, windowStage: window.WindowStage): void;

Called when the window stage of an ability is destroyed.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|
| windowStage | [window.WindowStage](js-apis-window.md#windowstage9) | Yes| **WindowStage** object.|


## AbilityLifecycleCallback.onAbilityDestroy

onAbilityDestroy(ability: Ability): void;

Called when an ability is destroyed.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|


## AbilityLifecycleCallback.onAbilityForeground

onAbilityForeground(ability: Ability): void;

Called when an ability is switched from the background to the foreground.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|


## AbilityLifecycleCallback.onAbilityBackground

onAbilityBackground(ability: Ability): void;

Called when an ability is switched from the foreground to the background.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|


## AbilityLifecycleCallback.onAbilityContinue

onAbilityContinue(ability: Ability): void;

Called when an ability is continued on another device.

**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| ability | [Ability](js-apis-application-ability.md#Ability) | Yes| **Ability** object.|

**Example**

```ts
import AbilityStage from "@ohos.app.ability.AbilityStage";

var lifecycleId;

export default class MyAbilityStage extends AbilityStage {
    onCreate() {
        console.log("MyAbilityStage onCreate")
        let AbilityLifecycleCallback = {
            onAbilityCreate(ability) {
                console.log("onAbilityCreate ability:" + JSON.stringify(ability));
            },
            onWindowStageCreate(ability, windowStage) {
                console.log("onWindowStageCreate ability:" + JSON.stringify(ability));
                console.log("onWindowStageCreate windowStage:" + JSON.stringify(windowStage));
            },
            onWindowStageActive(ability, windowStage) {
                console.log("onWindowStageActive ability:" + JSON.stringify(ability));
                console.log("onWindowStageActive windowStage:" + JSON.stringify(windowStage));
            },
            onWindowStageInactive(ability, windowStage) {
                console.log("onWindowStageInactive ability:" + JSON.stringify(ability));
                console.log("onWindowStageInactive windowStage:" + JSON.stringify(windowStage));
            },
            onWindowStageDestroy(ability, windowStage) {
                console.log("onWindowStageDestroy ability:" + JSON.stringify(ability));
                console.log("onWindowStageDestroy windowStage:" + JSON.stringify(windowStage));
            },
            onAbilityDestroy(ability) {
                console.log("onAbilityDestroy ability:" + JSON.stringify(ability));
            },
            onAbilityForeground(ability) {
                console.log("onAbilityForeground ability:" + JSON.stringify(ability));
            },
            onAbilityBackground(ability) {
                console.log("onAbilityBackground ability:" + JSON.stringify(ability));
            },
            onAbilityContinue(ability) {
                console.log("onAbilityContinue ability:" + JSON.stringify(ability));
            }
        }
        // 1. Obtain applicationContext through the context attribute.
        let applicationContext = this.context.getApplicationContext();
        // 2. Use applicationContext to register a listener for the ability lifecycle in the application.
        lifecycleId = applicationContext.registerAbilityLifecycleCallback(AbilityLifecycleCallback);
        console.log("registerAbilityLifecycleCallback number: " + JSON.stringify(lifecycleId));
    }

    onDestroy() {
        let applicationContext = this.context.getApplicationContext();
        applicationContext.unregisterAbilityLifecycleCallback(lifecycleId, (error, data) => {
            console.log("unregisterAbilityLifecycleCallback success, err: " + JSON.stringify(error));
        });
    }
}
```