HarmonyOS开发实例：【任务延时调度】

介绍

本示例使用[@ohos.WorkSchedulerExtensionAbility] 、[@ohos.net.http]、[@ohos.notification] 、[@ohos.bundle]、[@ohos.fileio] 等接口，实现了设置后台任务、下载更新包、保存更新包、发送通知、安装更新包实现升级的功能。

效果预览

使用说明

安装本应用之前，先编译好未签名的应用包，然后在终端执行工程里的脚本，目录为：WorkScheduler/signTool/b_sign_hap_release.bat；
未连接wifi状态下进入应用；
进入首页后连接wifi；
后台判断版本号后会下载新的升级包，并在页面中给出弹窗询问是否安装，点击“确定”按钮；
应用会安装已经下载的升级包，实现版本更新，安装后会回到设备桌面，此时点击应用图标，可以看到版本已经是新版本了。
运行自动化测试用例时，必须使用命令行装包，不能使用ide自动装包，安装自动化测试包之前，先编译好未签名的测试包，然后在终端执行工程里的脚本，目录为：WorkScheduler/signTool/a_sign_hap_release.bat；
运行自动化测试应用时需要使用如下命令：

hdc shell aa test -b ohos.samples.workschedulerextensionability -m entry_test -s unittest OpenHarmonyTestRunner -s class ActsAbilityTest -s timeout 150000

代码解读

entry/src/main/ets/
|---Application
|   |---MyAbilityStage.ets                  // 入口文件
|---feature
|   |---WorkSchedulerSystem.ets             // 封装各个功能接口
|---MainAbility
|   |---MainAbility.ets                     // 请求权限
|---pages
|   |---Index.ets                           // 首页
|---util
|   |---Logger.ets                          // 日志文件
|---WorkSchedulerAbility
|   |---WorkSchedulerAbility.ets            // 延时任务触发后的回调

搜狗高速浏览器截图20240326151547.png

具体实现

鸿蒙next开发知识更新在：gitee.com/li-shizhen-skin/harmony-os/blob/master/README.md

设置延时任务、下载更新包、保存更新包、发送通知、安装更新包的功能接口都封装在WorkSchedulerSystem中，源码参考：[WorkSchedulerSystem.ets]

/*

 * Copyright (c) 2023-2024 Huawei Device Co., Ltd.

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



import fs from '@ohos.file.fs';

import notificationManager from '@ohos.notificationManager';

import Notification from '@ohos.notification';

import bundle from '@ohos.bundle.installer';

import account from '@ohos.account.osAccount';

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

import http from '@ohos.net.http';

import { Logger } from '../utils/Logger';



const FILE_NAME = '/UpdateWorkScheduler.hap';

const BUNDLE_NAMES = ['ohos.samples.workschedulerextensionability'];

const INSTALL_PARAMETER = 1;



export namespace WorkSchedulerSystem {

  /**

   * Store the file to the specified directory.

   *

   * @param pathDir Path to save the file.

   * @param content The contents of the file to be saved.

   */

  export function saveFile(pathDir: string, content: ArrayBuffer): void {

    try {

      let filePath = pathDir + FILE_NAME;

      let fd = fs.openSync(filePath, 0o2 | 0o100).fd;

      fs.writeSync(fd, content);

      fs.closeSync(fd);

    } catch (err) {

      Logger.error(`saveFile failed, code is ${err.code}, message is ${err.message}`);

    }

  }



  /**

   * Sending a Notification.

   *

   * @param bundleName Check the name of the application that has permission.

   * @permission ohos.permission.NOTIFICATION_CONTROLLER

   */

  export async function handleNotification(bundleName: string): Promise<void> {

    await notificationManager.requestEnableNotification();

    Notification.subscribe({

      onConsume: (data) => {

        if (data.request.content.normal.text === 'isReady') {

          AppStorage.SetOrCreate('isShowDialog', true);

        }

      }

    }, {

      bundleNames: BUNDLE_NAMES

    })

  }



  /**

   * Publishes a notification of the specified content.

   *

   * @param title Title of Notice.

   * @param text Content of Notification Text.

   * @param additionalText Additional text.

   * @permission ohos.permission.NOTIFICATION_CONTROLLER

   */

  export function publishNotification(title: string, text: string, additionalText: string): void {

    notificationManager.publish({

      content: {

        contentType: Notification.ContentType.NOTIFICATION_CONTENT_BASIC_TEXT,

        normal: {

          title,

          text,

          additionalText

        }

      }

    })

  }



  /**

   * Install the application package in the specified path.

   *

   * @param filePath An array of paths to hold the installation package.

   * @permission ohos.permission.INSTALL_BUNDLE

   */

  export async function installBundle(filePath: Array<string>): Promise<void> {

    try {

      let bundleInstall = await bundle.getBundleInstaller();

      let userId = await account.getAccountManager().getOsAccountLocalIdFromProcess();

      bundleInstall.install(filePath, {

        userId: userId,

        installFlag: INSTALL_PARAMETER,

        isKeepData: false

      }, (status, statusMessage) => {

        Logger.info(`installBundle filepath is ${filePath}`);

        Logger.info(`installBundle code is ${status.code}, message is ${JSON.stringify(statusMessage)}`);

      })

    } catch (err) {

      Logger.error(`installBundle failed, code is ${err.code}, message is ${err.message}`);

    }

  }



  /**

   * Register the delayed task and pass the parameters.

   *

   * @param version Current application version.

   * @param bundleName The name of the application package for which the task needs to be registered.

   * @param filePath Storage address of the application package.

   */

  export async function startUpdateSample(version: string, bundleName: string, filePath: string): Promise<void> {

    try {

      let workInfo = {

        workId: 1,

        bundleName: bundleName,

        abilityName: 'WorkSchedulerAbility',

        networkType: workScheduler.NetworkType.NETWORK_TYPE_WIFI,

        parameters: {

          version: version,

          filePath: filePath

        }

      };

      workScheduler.startWork(workInfo);

    }

    catch (err) {

      Logger.error(`startWork failed, code is ${err.code}, message is ${err.message}`);

    }

  }



  /**

   * Register the delayed task and pass the parameters.

   *

   * @param url Url of the application package.

   * @permission ohos.permission.INTERNET

   */

  export async function getNewHap(url: string): Promise<http.HttpResponse> {

    try {

      return await http.createHttp().request(

        url,

        {

          expectDataType: http.HttpDataType.ARRAY_BUFFER

        });

    } catch (err) {

      Logger.error(`get result failed, code is ${err.code}, message is ${err.message}`);

    }

  }

}

设置延时任务：在运行示例时会在[MainAbility.ets] 通过WorkSchedulerSystem.startUpdateSample()方法调用workScheduler.startWork()建立任务；
下载更新包：当任务条件满足后，会在[WorkSchedulerAbility.ets]通过WorkSchedulerSystem.getNewHap()方法调用http.createHttp().request()接口下载需要的文件；
保存更新包：通过WorkSchedulerSystem.saveFile()来实现，受限调用fileio.openSync()创建文件，然后调用fileio.writeSync()将下载的内容写入指定文件内；
发送通知：在[WorkSchedulerAbility.ets] 中通过WorkSchedulerSystem.publishNotification()方法，调用Notification.publish()接口发送指定内容的信息；
接收通知：在[MainAbility.ets]中通过WorkSchedulerSystem.handleNotification()方法调用Notification.subscribe()接口获取信息，根据信息内容决定是否提示用户升级；
安装更新包：在[WorkSchedulerAbility.ets] 通过WorkSchedulerSystem.installBundle()方法实现，首先调用bundle.getBundleInstaller()获取Installer对象，然后调用bundleInstall.install()接口实现装包，完成升级。

最后呢，很多开发朋友不知道需要学习那些鸿蒙技术？鸿蒙开发岗位需要掌握那些核心技术点？为此鸿蒙的开发学习必须要系统性的进行。

而网上有关鸿蒙的开发资料非常的少，假如你想学好鸿蒙的应用开发与系统底层开发。你可以参考这份资料，少走很多弯路，节省没必要的麻烦。由两位前阿里高级研发工程师联合打造的《鸿蒙NEXT星河版OpenHarmony开发文档》里面内容包含了（ArkTS、ArkUI开发组件、Stage模型、多端部署、分布式应用开发、音频、视频、WebGL、OpenHarmony多媒体技术、Napi组件、OpenHarmony内核、Harmony南向开发、鸿蒙项目实战等等）鸿蒙（Harmony NEXT）技术知识点

如果你是一名Android、Java、前端等等开发人员，想要转入鸿蒙方向发展。可以直接领取这份资料辅助你的学习。下面是鸿蒙开发的学习路线图。