harmony 鸿蒙@ohos.resourceschedule.deviceStandby (Device Standby) (System API)

2025-06-12
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@ohos.resourceschedule.deviceStandby (Device Standby) (System API)

A device enters standby mode if it is unused for a long period of time or after the Power button is pressed. The standby mode prolongs the battery life without affecting the use of applications. The deviceStandby module provides APIs for you to check whether a device is in standby mode and request or cancel standby resource control for an application.

NOTE

The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version.

The APIs provided by this module are system APIs.

Modules to Import

import deviceStandby from '@ohos.resourceschedule.deviceStandby';

deviceStandby.getExemptedApps

getExemptedApps(resourceTypes: number, callback: AsyncCallback): void

Obtains the list of applications that can still use resources of the specified types when the device is in standby mode. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Required permissions: ohos.permission.DEVICE_STANDBY_EXEMPTION

Parameters

Name	Type	Mandatory	Description
ResourceTypes	number	Yes	Resource types. For details, see ResourceType.
callback	AsyncCallback	Yes	Callback used to return the exempted application information.

Error codes

For details about the error codes, see Universal Error Codes and backgroundTaskManager Error Codes.

ID	Error Message
201	Permission denied.
202	Not System App.
401	Parameter error.
9800001	Memory operation failed.
9800002	Parcel operation failed.
9800003	Inner transact failed.
9800004	System service operation failed.
18700001	Caller information verification failed.

Example

import { BusinessError } from '@ohos.base';

let resourceTypes: deviceStandby.ResourceType  = deviceStandby.ResourceType.TIMER|deviceStandby.ResourceType.NETWORK;
deviceStandby.getExemptedApps(resourceTypes, (err: BusinessError, res: Array<deviceStandby.ExemptedAppInfo>) => {
  if (err) {
    console.log('DEVICE_STANDBY getExemptedApps callback failed. code is: ' + err.code + ',message is: ' + err.message);
  } else {
    console.log('DEVICE_STANDBY getExemptedApps callback success.');
    for (let i = 0; i < res.length; i++) {
      console.log('DEVICE_STANDBY getExemptedApps callback result ' + JSON.stringify(res[i]));
    }
  }
});

deviceStandby.getExemptedApps

getExemptedApps(resourceTypes: number): Promise

Obtains the list of applications that can still use resources of the specified types when the device is in standby mode. This API uses a promise to return the result.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Required permissions: ohos.permission.DEVICE_STANDBY_EXEMPTION

Parameters

Name	Type	Mandatory	Description
ResourceTypes	number	Yes	Resource types. For details, see ResourceType.

Return value

Type	Description
Promise	Promise used to return the exempted application information.

Error codes

For details about the error codes, see Universal Error Codes and backgroundTaskManager Error Codes.

ID	Error Message
201	Permission denied.
202	Not System App.
401	Parameter error.
9800001	Memory operation failed.
9800002	Parcel operation failed.
9800003	Inner transact failed.
9800004	System service operation failed.
18700001	Caller information verification failed.

Example

import { BusinessError } from '@ohos.base';

let resourceTypes: deviceStandby.ResourceType = deviceStandby.ResourceType.TIMER|deviceStandby.ResourceType.NETWORK;
deviceStandby.getExemptedApps(resourceTypes).then( (res: Array<deviceStandby.ExemptedAppInfo>) => {
  console.log('DEVICE_STANDBY getExemptedApps promise success.');
  for (let i = 0; i < res.length; i++) {
    console.log('DEVICE_STANDBY getExemptedApps promise result ' + JSON.stringify(res[i]));
  }
}).catch( (err: BusinessError) => {
  console.log('DEVICE_STANDBY getExemptedApps promise failed. code is: ' + err.code + ',message is: ' + err.message);
});

deviceStandby.requestExemptionResource

requestExemptionResource(request: ResourceRequest): void

Requests exemption, so that the application can use restricted resources when the device is in standby mode.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Required permissions: ohos.permission.DEVICE_STANDBY_EXEMPTION

Parameters

Name	Type	Mandatory	Description
request	ResourceRequest	Yes	Request body.

Error codes

For details about the error codes, see Universal Error Codes and backgroundTaskManager Error Codes.

ID	Error Message
201	Permission denied.
202	Not System App.
401	Parameter error.
9800001	Memory operation failed.
9800002	Parcel operation failed.
9800003	Inner transact failed.
9800004	System service operation failed.
18700001	Caller information verification failed.

Example

let resRequest: deviceStandby.ResourceRequest = {
  resourceTypes: deviceStandby.ResourceType.TIMER,
  uid:10003,
  name:"com.example.app",
  duration:10,
  reason:"apply",
};
deviceStandby.requestExemptionResource(resRequest);

deviceStandby.releaseExemptionResource

releaseExemptionResource(request: ResourceRequest): void

Cancels exemption for the application.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Required permissions: ohos.permission.DEVICE_STANDBY_EXEMPTION

Parameters

Name	Type	Mandatory	Description
request	ResourceRequest	Yes	Request body.

Error codes

For details about the error codes, see Universal Error Codes and backgroundTaskManager Error Codes.

ID	Error Message
201	Permission denied.
202	Not System App.
401	Parameter error.
9800001	Memory operation failed.
9800002	Parcel operation failed.
9800003	Inner transact failed.
9800004	System service operation failed.
18700001	Caller information verification failed.

Example

let resRequest: deviceStandby.ResourceRequest = {
  resourceTypes: deviceStandby.ResourceType.TIMER,
  uid:10003,
  name:"com.demo.app",
  duration:10,
  reason:"unapply",
};
deviceStandby.releaseExemptionResource(resRequest);

ResourceType

Enumerates the types of resources that can be used by exempted applications.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Name	Value	Description
NETWORK	1	Network access resource.
RUNNING_LOCK	2	CPU running lock resource.
TIMER	4	Timer task resource.
WORK_SCHEDULER	8	Work task resource.
AUTO_SYNC	16	Automatic synchronization resource.
PUSH	32	Push kit resource.
FREEZE	64	Freezing application resource.

ExemptedAppInfo

Defines the information about an exempted application.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Name	Type	Mandatory	Description
resourceTypes	number	Yes	Resource types. For details, see ResourceType.
name	string	Yes	Name of the application.
duration	number	Yes	Exemption duration.

ResourceRequest

Defines the message used to request to be an exempted application.

System capability: SystemCapability.ResourceSchedule.DeviceStandby

Name	Type	Mandatory	Description
resourceTypes	number	Yes	Resource types. For details, see ResourceType.
uid	number	Yes	UID of the application.
name	string	Yes	Name of the application.
duration	number	Yes	Exemption duration.
reason	string	Yes	Reason for the request.