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

表2 WorkInfo包含参数

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

表3 延迟任务回调接口

接口名	接口描述
function onWorkStart(work: WorkInfo): void;	延迟调度任务开始回调
function 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);
  });
})