@ohos.app.ability.AbilityConstant (AbilityConstant)

The AbilityConstant module defines the ability-related enums, including the initial launch reasons, reasons for the last exit, ability continuation results, and window modes.

NOTE

The initial APIs of this module are supported since API version 9. 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

import AbilityConstant from '@ohos.app.ability.AbilityConstant';

Attributes

AbilityConstant.LaunchParam

Defines the parameters for starting an ability.

System capability: SystemCapability.Ability.AbilityRuntime.Core

AbilityConstant.LaunchReason

Enumerates the initial ability launch reasons. You can use it together with onCreate(want, launchParam) of Ability to complete different operations.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import UIAbility from '@ohos.app.ability.UIAbility';

class MyAbility extends UIAbility {
    onCreate(want, launchParam) {
        if (launchParam.launchReason === AbilityConstant.LaunchReason.START_ABILITY) {
            console.log('The ability has been started by the way of startAbility.');
        }
    }
}

AbilityConstant.LastExitReason

Enumerates the reasons for the last exit. You can use it together with onCreate(want, launchParam) of Ability to complete different operations.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import UIAbility from '@ohos.app.ability.UIAbility';

class MyAbility extends UIAbility {
    onCreate(want, launchParam) {
        if (launchParam.lastExitReason === AbilityConstant.LastExitReason.ABILITY_NOT_RESPONDING) {
            console.log('The ability has exit last because the ability was not responding.');
        }
    }
}

AbilityConstant.OnContinueResult

Enumerates the ability continuation results. You can use it together with onContinue(wantParam) of Ability to complete different operations.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import UIAbility from '@ohos.app.ability.UIAbility';

class MyAbility extends UIAbility {
    onContinue(wantParam) {
        return AbilityConstant.OnContinueResult.AGREE;
    }
}

AbilityConstant.WindowMode

Enumerates the window modes in which an ability can be displayed at startup. It can be used in startAbility() to specify the window mode when the ability is started.

System capability: SystemCapability.Ability.AbilityRuntime.Core

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

Example

let want = {
    bundleName: 'com.example.myapplication',
    abilityName: 'EntryAbility'
};
let option = {
    windowMode: AbilityConstant.WindowMode.WINDOW_MODE_FULLSCREEN
};

// Ensure that the context is obtained.
this.context.startAbility(want, option).then(()=>{
    console.log('Succeed to start ability.');
}).catch((error)=>{
    console.error('Failed to start ability with error: ${JSON.stringify(error)}');
});

AbilityConstant.MemoryLevel

Enumerates the memory levels. You can use it in onMemoryLevel(level) of Ability to complete different operations.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import UIAbility from '@ohos.app.ability.UIAbility';

class MyAbility extends UIAbility {
    onMemoryLevel(level) {
        if (level === AbilityConstant.MemoryLevel.MEMORY_LEVEL_CRITICAL) {
            console.log('The memory of device is critical, please release some memory.');
        }
    }
}

AbilityConstant.OnSaveResult

Enumerates the result types for the operation of saving application data. You can use it in onSaveState(reason, wantParam) of Ability to complete different operations.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import UIAbility from '@ohos.app.ability.UIAbility';

class MyAbility extends UIAbility {
    onSaveState(reason, wantParam) {
        return AbilityConstant.OnSaveResult.ALL_AGREE;
    }
}

AbilityConstant.StateType

Enumerates the scenarios for saving application data. You can use it in onSaveState(reason, wantParam) of Ability to complete different operations.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import UIAbility from '@ohos.app.ability.UIAbility';

class MyAbility extends UIAbility {
    onSaveState(reason, wantParam) {
        if (reason === AbilityConstant.StateType.CONTINUATION) {
            console.log('Save the ability data when the ability continuation.');
        } 
        return AbilityConstant.OnSaveResult.ALL_AGREE;
    }
}