@ohos.app.ability.AbilityConstant (AbilityConstant)

The AbilityConstant module defines the UIAbility-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 '@kit.AbilityKit';

LaunchParam

Defines the parameters for starting an ability. The parameter values are automatically passed in by the system when the ability is started. You do not need to change the values.

System capability: SystemCapability.Ability.AbilityRuntime.Core

LaunchReason

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

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, Want, AbilityConstant } from '@kit.AbilityKit';

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

LastExitReason

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

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, Want, AbilityConstant } from '@kit.AbilityKit';

class MyAbility extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
    if (launchParam.lastExitReason === AbilityConstant.LastExitReason.APP_FREEZE) {
      console.log('The ability has exit last because the ability was not responding.');
    }
    if (launchParam.lastExitReason === AbilityConstant.LastExitReason.RESOURCE_CONTROL) {
      console.log('The ability has exit last because the rss control, the lastExitReason is '+ launchParam.lastExitReason + ', the lastExitMessage is ' + launchParam.lastExitMessage);
    }
  }
}

LastExitDetailInfo¹⁸⁺

Describes the detailed information about the last exit.

Atomic service API: This API can be used in atomic services since API version 18.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, Want, AbilityConstant } from '@kit.AbilityKit';

class MyAbility extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
    if (launchParam.lastExitDetailInfo) {
      console.log('pid: ' + launchParam.lastExitDetailInfo.pid +
        '\n processName: ' + launchParam.lastExitDetailInfo.processName +
        '\n uid: ' + launchParam.lastExitDetailInfo.uid +
        '\n exitSubReason: ' + launchParam.lastExitDetailInfo.exitSubReason +
        '\n exitMsg: ' + launchParam.lastExitDetailInfo.exitMsg +
        '\n rss: ' + launchParam.lastExitDetailInfo.rss +
        '\n pss: ' + launchParam.lastExitDetailInfo.pss +
        '\n timestamp: ' + launchParam.lastExitDetailInfo.timestamp
      );
    }
  }
}

OnContinueResult

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

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, AbilityConstant } from '@kit.AbilityKit';

class MyAbility extends UIAbility {
  onContinue(wantParam: Record<string, Object>) {
    return AbilityConstant.OnContinueResult.AGREE;
  }
}

MemoryLevel

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

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

NOTE

The trigger conditions may differ across various devices. For example, on a standard device with 12 GB of memory: - A callback with value 0 is triggered when available memory drops between 1700 MB and 1800 MB. - A callback with value 1 is triggered when available memory drops between 1600 MB and 1700 MB. - A callback with value 2 is triggered when available memory falls below 1600 MB.

Example

import { UIAbility, AbilityConstant } from '@kit.AbilityKit';

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

WindowMode¹²⁺

Enumerates the window mode when the ability is started. It can be used together with startAbility to specify the window mode for starting the ability.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, StartOptions, Want, AbilityConstant } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

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

// Ensure that the context is obtained.
class MyAbility extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
    this.context.startAbility(want, option).then(() => {
      console.log('Succeed to start ability.');
    }).catch((error: BusinessError) => {
      console.error(`Failed to start ability with error: ${JSON.stringify(error)}`);
    });
  }
}

OnSaveResult

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

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, AbilityConstant } from '@kit.AbilityKit';

class MyAbility extends UIAbility {
  onSaveState(reason: AbilityConstant.StateType, wantParam: Record<string, Object>) {
    return AbilityConstant.OnSaveResult.ALL_AGREE;
  }
}

StateType

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

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, AbilityConstant } from '@kit.AbilityKit';

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

ContinueState¹⁰⁺

Enumerates the mission continuation states of the application. It is used in the setMissionContinueState API of UIAbilityContext.

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, Want, AbilityConstant } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

class MyAbility extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
    this.context.setMissionContinueState(AbilityConstant.ContinueState.INACTIVE, (result: BusinessError) => {
      console.info(`setMissionContinueState: ${JSON.stringify(result)}`);
    });
  }
}

CollaborateResult¹⁸⁺

Enumerates the collaboration request results. This enum is used in multi-device collaboration scenarios to specify whether the target application accepts the collaboration request from the caller application. It is used in onCollaborate(wantParam) of the UIAbility.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { UIAbility, AbilityConstant } from '@kit.AbilityKit';

class MyAbility extends UIAbility {
  onCollaborate(wantParam: Record<string, Object>) {
    return AbilityConstant.CollaborateResult.ACCEPT;
  }
}

PrepareTermination¹⁵⁺

Enumerates the actions triggered when an application is closed by the user. It must be used together with onPrepareTermination or onPrepareTerminationAsync of AbilityStage.

Atomic service API: This API can be used in atomic services since API version 15.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Example

import { AbilityConstant, AbilityStage } from '@kit.AbilityKit';

class MyAbilityStage extends AbilityStage {
  onPrepareTermination(): AbilityConstant.PrepareTermination {
    console.info('MyAbilityStage.onPrepareTermination is called');
    return AbilityConstant.PrepareTermination.CANCEL;
  }
}

你可能感兴趣的鸿蒙文章

harmony 鸿蒙Ability Kit

harmony 鸿蒙AbilityAccessControl

harmony 鸿蒙AbilityBase

harmony 鸿蒙AbilityBase_Element

harmony 鸿蒙AbilityRuntime

harmony 鸿蒙bundle

harmony 鸿蒙OH_NativeBundle_ApplicationInfo

harmony 鸿蒙OH_NativeBundle_ElementName

harmony 鸿蒙ability_access_control.h

harmony 鸿蒙ability_base_common.h