@ohos.app.ability.AbilityConstant (AbilityConstant)

AbilityConstant提供Ability相关的枚举，包括设置初次启动原因、上次退出原因、迁移结果、窗口类型等。

说明：

本模块首批接口从API version 9开始支持。后续版本的新增接口，采用上角标单独标记接口的起始版本。
本模块接口仅可在Stage模型下使用。

导入模块

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

属性

AbilityConstant.LaunchParam

启动参数。

系统能力：以下各项对应的系统能力均为SystemCapability.Ability.AbilityRuntime.Core

AbilityConstant.LaunchReason

Ability初次启动原因，该类型为枚举，可配合Ability的onCreate(want, launchParam)方法根据launchParam.launchReason的不同类型执行相应操作。

系统能力：SystemCapability.Ability.AbilityRuntime.Core

示例：

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

Ability上次退出原因，该类型为枚举，可配合Ability的onCreate(want, launchParam)方法根据launchParam.lastExitReason的不同类型执行相应操作。

系统能力：SystemCapability.Ability.AbilityRuntime.Core

示例：

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

Ability迁移结果，该类型为枚举，可配合Ability的onContinue(wantParam)方法进完成相应的返回。

系统能力：SystemCapability.Ability.AbilityRuntime.Core

示例：

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

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

AbilityConstant.WindowMode

启动Ability时的窗口模式，该类型为枚举，可配合startAbility使用指定启动Ability的窗口模式。

系统能力：以下各项对应的系统能力均为SystemCapability.Ability.AbilityRuntime.Core

系统API: 此接口为系统接口，三方应用不支持调用。

示例：

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

// 确保从上下文获取到context
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

内存级别，该类型为枚举，可配合Ability的onMemoryLevel(level)方法根据level执行不同内存级别的相应操作。

系统能力：以下各项对应的系统能力均为SystemCapability.Ability.AbilityRuntime.Core

示例：

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

保存应用数据的结果，该类型为枚举，可配合Ability的onSaveState(reason, wantParam)方法完成相应的返回。

系统能力：以下各项对应的系统能力均为SystemCapability.Ability.AbilityRuntime.Core

示例：

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

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

AbilityConstant.StateType

保存应用数据场景原因，该类型为枚举，可配合Ability的onSaveState(reason, wantParam)方法根据reason的不同类型执行相应操作。

系统能力：以下各项对应的系统能力均为SystemCapability.Ability.AbilityRuntime.Core

示例：

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;
    }
}