延迟任务调度开发指导

场景介绍

应用要执行对实时性要求不高的任务的时候，比如设备空闲时候做一次数据学习等场景，可以使用延迟调度任务，该机制在满足应用设定条件的时候，会根据系统当前状态，如内存、功耗、热等统一决策调度时间。

接口说明

注册相关接口包导入：

import workScheduler from '@ohos.workScheduler';

回调相关接口包导入：

import WorkSchedulerExtensionAbility from '@ohos.WorkSchedulerExtensionAbility';

延迟任务调度

表1 workScheduler主要接口

接口名	接口描述
startWork(work: WorkInfo): boolean	延迟调度任务申请
stopWork(work: WorkInfo, needCancel?: boolean): boolean	延迟调度任务取消
getWorkStatus(workId: number, callback: AsyncCallback<WorkInfo>): void	获取延迟调度任务状态（Callback形式）
getWorkStatus(workId: number): Promise<WorkInfo>	获取延迟调度任务状态（Promise形式）
obtainAllWorks(callback: AsyncCallback<void>): Array<WorkInfo>	获取所有延迟调度任务（Callback形式）
obtainAllWorks(): Promise<Array<WorkInfo>>	获取所有延迟调度任务（Promise形式）
stopAndClearWorks(): boolean	停止并清除任务
isLastWorkTimeOut(workId: number, callback: AsyncCallback<void>): boolean	获取上次任务是否超时（针对RepeatWork，Callback形式）
isLastWorkTimeOut(workId: number): Promise<boolean>	获取上次任务是否超时（针对RepeatWork，Promise形式）

表2 WorkInfo包含参数

说明： WorkInfo设置参数约束见延迟任务调度概述

参数名	类型	描述
workId	number	延迟任务Id（必填）
bundleName	string	延迟任务包名（必填）
abilityName	string	延迟任务回调通知的组件名（必填）
networkType	NetworkType	网络类型
isCharging	boolean	是否充电
chargerType	ChargingType	充电类型
batteryLevel	number	电量
batteryStatus	BatteryStatus	电池状态
storageRequest	StorageRequest	存储状态
isRepeat	boolean	是否循环任务
repeatCycleTime	number	循环间隔
repeatCount	number	循环次数

表3 延迟任务回调接口

接口名	接口描述
onWorkStart(work: WorkInfo): void	延迟调度任务开始回调
onWorkStop(work: WorkInfo): void	延迟调度任务结束回调

开发步骤

开发对应的Extension

import WorkSchedulerExtensionAbility from '@ohos.WorkSchedulerExtensionAbility';

export default class MyWorkSchedulerExtensionAbility extends WorkSchedulerExtensionAbility {
    onWorkStart(workInfo) {
        console.log('MyWorkSchedulerExtensionAbility onWorkStart' + JSON.stringify(workInfo));
    }
    onWorkStop(workInfo) {
        console.log('MyWorkSchedulerExtensionAbility onWorkStop' + JSON.stringify(workInfo));
    }
}

注册延迟任务

import workScheduler from '@ohos.workScheduler';

let workInfo = {
    workId: 1,
    batteryLevel:50,
    batteryStatus:workScheduler.BatteryStatus.BATTERY_STATUS_LOW,
    isRepeat: false,
    isPersisted: true,
    bundleName: "com.example.myapplication",
    abilityName: "MyExtension"
}
var res = workScheduler.startWork(workInfo);
console.info("workschedulerLog res:" + res);

取消延迟任务

import workScheduler from '@ohos.workScheduler';

let workInfo = {
    workId: 1,
    batteryLevel:50,
    batteryStatus:workScheduler.BatteryStatus.BATTERY_STATUS_LOW,
    isRepeat: false,
    isPersisted: true,
    bundleName: "com.example.myapplication",
    abilityName: "MyExtension"
}
var res = workScheduler.stopWork(workInfo, false);
console.info("workschedulerLog res:" + res);

获取指定延迟任务

1.Callback写法

workScheduler.getWorkStatus(50, (err, res) => {
  if (err) {
    console.info('workschedulerLog getWorkStatus failed, because:' + err.data);
  } else {
    for (let item in res) {
      console.info('workschedulerLog getWorkStatuscallback success,' + item + ' is:' + res[item]);
    }
  }
});

2.Promise写法

workScheduler.getWorkStatus(50).then((res) => {
  for (let item in res) {
    console.info('workschedulerLog getWorkStatus success,' + item + ' is:' + res[item]);
  }
}).catch((err) => {
  console.info('workschedulerLog getWorkStatus failed, because:' + err.data);
})

获取所有延迟任务

1.Callback写法

workScheduler.obtainAllWorks((err, res) =>{
  if (err) {
    console.info('workschedulerLog obtainAllWorks failed, because:' + err.data);
  } else {
    console.info('workschedulerLog obtainAllWorks success, data is:' + JSON.stringify(res));
  }
});

2.Promise写法

workScheduler.obtainAllWorks().then((res) => {
  console.info('workschedulerLog obtainAllWorks success, data is:' + JSON.stringify(res));
}).catch((err) => {
  console.info('workschedulerLog obtainAllWorks failed, because:' + err.data);
})

停止并清除任务

let res = workScheduler.stopAndClearWorks();
console.info("workschedulerLog res:" + res);

判断上次执行是否超时

1.Callback写法

workScheduler.isLastWorkTimeOut(500, (err, res) =>{
  if (err) {
    console.info('workschedulerLog isLastWorkTimeOut failed, because:' + err.data);
  } else {
    console.info('workschedulerLog isLastWorkTimeOut success, data is:' + res);
  }
});

2.Promise写法

workScheduler.isLastWorkTimeOut(500)
  .then(res => {
    console.info('workschedulerLog isLastWorkTimeOut success, data is:' + res);
  })
  .catch(err =>  {
    console.info('workschedulerLog isLastWorkTimeOut failed, because:' + err.data);
  });
})