HarmonyOS应用三之组件生命周期和参数传递

1、生命周期的执行顺序

/*
 * Copyright (c) 2023 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 { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';

export default class EntryAbility extends UIAbility {
  windowStage: window.WindowStage | undefined = undefined;
  tag: string = 'EntryAbility';
  domain: number = 0x0000;
  want: Want | undefined = undefined;
  launchParam: AbilityConstant.LaunchParam | undefined = undefined;
  windowStageEventFunc: (data: window.WindowStageEventType) => void = (data: window.WindowStageEventType): void => {
    hilog.info(
      this.domain,
      'Succeeded in enabling the listener for window stage event changes. Data: %{public}',
      JSON.stringify(data) ?? ''
    );
  }

  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
    this.want = want;
    this.launchParam = launchParam;
    hilog.info(this.domain, this.tag, 'Ability is onCreate.');
  }

  onDestroy() {
    hilog.info(this.domain, this.tag, 'Ability is onDestroy.');
  }

  onWindowStageCreate(windowStage: window.WindowStage) {
    this.windowStage = windowStage;

    // Setting Event Subscription for WindowStage (Obtained/Out-of-focus, Visible/Invisible)
    try {
      windowStage.on('windowStageEvent', this.windowStageEventFunc);
    } catch (exception) {
      hilog.error(
        this.domain,
        'Failed to enable the listener for window stage event changes. Cause: %{public}',
        JSON.stringify(exception) ?? ''
      );
    }

    // Main window is created, set main page for this ability
    // Setting UI Loading
    windowStage.loadContent('pages/LifeCyclePage', (err, data) => {
      if (err.code) {
        hilog.error(this.domain, 'testTag', 'Failed to load the content. Cause: %{public}s',
          JSON.stringify(err) ?? '');
        return;
      }
      hilog.info(this.domain, this.tag, 'Succeeded in loading the content. Data: %{public}s',
        JSON.stringify(data) ?? '');
    });
  }

  onWindowStageDestroy() {
    // Releasing UI Resources
    // Unregisters the WindowStage event for getting/out of focus in onWindowStageDestroy()
    try {
      this.windowStage?.off('windowStageEvent');
    } catch (exception) {
      hilog.error(this.domain, 'Failed to disable the listener for window stage event changes. Cause: %{public}s',
        JSON.stringify(exception));
    }
  }

  onForeground() {
    // Ability has brought to foreground
    hilog.info(this.domain, this.tag, 'Ability is onForeground.');
  }

  onBackground() {
    // Ability has back to background
    hilog.info(this.domain, this.tag, 'Ability is onBackground.');
  }
}

/*
 * Copyright (c) 2023 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 Logger from '../common/util/Logger';
import CommonConstants from '../common/constants/CommonConstants';

@Entry
@Component
struct LifeCyclePage {
  @State textColor: Color = Color.Black;

  aboutToAppear() {
    this.textColor = Color.Blue;
    Logger.info('[LifeCyclePage]  LifeCyclePage aboutToAppear');
  }

  onPageShow() {
    this.textColor = Color.Brown;
    Logger.info('[LifeCyclePage]  LifeCyclePage onPageShow');
  }

  onPageHide() {
    Logger.info('[LifeCyclePage]  LifeCyclePage onPageHide');
  }

  onBackPress() {
    this.textColor = Color.Red;
    Logger.info('[LifeCyclePage]  LifeCyclePage onBackPress');
    return false;
  }

  aboutToDisappear() {
    Logger.info('[LifeCyclePage]  LifeCyclePage aboutToDisappear');
  }

  build() {
    Column() {
      Text($r('app.string.hello_message'))
        .fontSize(CommonConstants.DEFAULT_FONT_SIZE)
        .fontColor(this.textColor)
        .margin(CommonConstants.DEFAULT_MARGIN)
        .fontWeight(FontWeight.Bold)
    }
    .width(CommonConstants.FULL_WIDTH)
  }
}

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2、页面数据传递

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首页跳转第二页时通过router.pushUrl中的routerParams来传递参数。

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第二页可以通过router.getParams().src来拿传递过来的值，展示到页面。

3、图片的读取

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app.media.banner_pic1读取的就是本地目录media下的该图片。

4、数据的备份和恢复

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BackupExtensionAbility模块提供备份恢复服务相关扩展能力，为应用提供扩展的备份恢复能力。
onBackup(): void; Extension生命周期回调，在执行备份数据时回调，由开发者提供扩展的备份数据的操作。
onRestore(bundleVersion: BundleVersion): void;Extension生命周期回调，在执行恢复数据时回调，由开发者提供扩展的恢复数据的操作。
当需要进行数据备份时，‌可以通过实现onBackup()方法来实现备份逻辑（可以通过脚本来实现）。‌
当需要进行数据恢复时，‌可以通过实现onRestore()方法来实现恢复逻辑（可以通过脚本来实现）。‌

5、轮播图

class BannerClass {
  id: string = '';
  imageSrc: ResourceStr = '';
  url: string = '';

  constructor(id: string, imageSrc: ResourceStr, url: string) {
    this.id = id;
    this.imageSrc = imageSrc;
    this.url = url;
  }
}

@Entry
@Component
struct Index {
  @State message: string = '快速入门';

  build() {
    Column() {
      Text(this.message)
        .fontSize(24)
        .fontWeight(700)
        .width('100%')
        .textAlign(TextAlign.Start)
        .padding({ left: 16 })
        .fontFamily('HarmonyHeiTi-Bold')
        .lineHeight(33)
      Banner()
    }
    .width('100%')
    .height('100%')
    .backgroundColor('#F1F3F5')
  }
}

@Preview
@Component
struct Banner {
  @State bannerList: Array<BannerClass> = [
    new BannerClass('pic0', $r('app.media.banner_pic0'),
      'https://developer.huawei.com/consumer/cn/training/course/video/C101718352529709527'),
    new BannerClass('pic1', $r('app.media.banner_pic1'),
      'https://developer.huawei.com/consumer/cn/'),
    new BannerClass('pic2', $r('app.media.banner_pic2'),
      'https://developer.huawei.com/consumer/cn/deveco-studio/'),
    new BannerClass('pic3', $r('app.media.banner_pic3'),
      'https://developer.huawei.com/consumer/cn/arkts/'),
    new BannerClass('pic4', $r('app.media.banner_pic4'),
      'https://developer.huawei.com/consumer/cn/arkui/'),
    new BannerClass('pic5', $r('app.media.banner_pic5'),
      'https://developer.huawei.com/consumer/cn/sdk')
  ];

  build() {
    Swiper() {
      ForEach(this.bannerList, (item: BannerClass, index: number) => {
        Image(item.imageSrc)
          .objectFit(ImageFit.Contain)
          .width('100%')
          .padding({ top: 11, left: 16, right: 16 })
          .borderRadius(16)
      }, (item: BannerClass, index: number) => item.id)
    }
    .autoPlay(true)
    .loop(true)
    .indicator(
      new DotIndicator()
        .color('#1a000000')
        .selectedColor('#0A59F7'))
  }
}

在这里插入图片描述

使用数组存储轮播图片，遍历展示。

loop：设置是否启用循环滑动时调用。
autoPlay：设置子组件是否自动播放时调用。
indicator：设置指示器已启用，或设置类型样式。

6、页面布局图

在这里插入图片描述

class BannerClass {
  id: string = '';
  imageSrc: ResourceStr = '';
  url: string = '';

  constructor(id: string, imageSrc: ResourceStr, url: string) {
    this.id = id;
    this.imageSrc = imageSrc;
    this.url = url;
  }
}

class ArticleClass {
  id: string = '';
  imageSrc: ResourceStr = '';
  title: string = '';
  brief: string = '';
  webUrl: string = '';

  constructor(id: string, imageSrc: ResourceStr, title: string, brief: string, webUrl: string) {
    this.id = id;
    this.imageSrc = imageSrc;
    this.title = title;
    this.brief = brief;
    this.webUrl = webUrl;
  }
}

@Entry
@Component
struct Index {
  @State message: string = '快速入门';

  build() {
    Column() {
      Text(this.message)
        .fontSize(24)
        .fontWeight(700)
        .width('100%')
        .textAlign(TextAlign.Start)
        .padding({ left: 16 })
        .fontFamily('HarmonyHeiTi-Bold')
        .lineHeight(33)
      Scroll() {
        Column() {
          Banner()
          EnablementView()
          TutorialView()
        }
      }
      .layoutWeight(1)
      .scrollBar(BarState.Off)
      .align(Alignment.TopStart)
    }
    .width('100%')
    .height('100%')
    .backgroundColor('#F1F3F5')
  }
}

@Preview
@Component
struct Banner {
  @State bannerList: Array<BannerClass> = [
    new BannerClass('pic0', $r('app.media.banner_pic0'),
      'https://developer.huawei.com/consumer/cn/training/course/video/C101718352529709527'),
    new BannerClass('pic1', $r('app.media.banner_pic1'),
      'https://developer.huawei.com/consumer/cn/'),
    new BannerClass('pic2', $r('app.media.banner_pic2'),
      'https://developer.huawei.com/consumer/cn/deveco-studio/'),
    new BannerClass('pic3', $r('app.media.banner_pic3'),
      'https://developer.huawei.com/consumer/cn/arkts/'),
    new BannerClass('pic4', $r('app.media.banner_pic4'),
      'https://developer.huawei.com/consumer/cn/arkui/'),
    new BannerClass('pic5', $r('app.media.banner_pic5'),
      'https://developer.huawei.com/consumer/cn/sdk')
  ];

  build() {
    Swiper() {
      ForEach(this.bannerList, (item: BannerClass, index: number) => {
        Image(item.imageSrc)
          .objectFit(ImageFit.Contain)
          .width('100%')
          .padding({ top: 11, left: 16, right: 16 })
          .borderRadius(16)
      }, (item: BannerClass, index: number) => item.id)
    }
    .autoPlay(true)
    .loop(true)
    .indicator(
      new DotIndicator()
        .color('#1a000000')
        .selectedColor('#0A59F7'))
  }
}

@Component
struct TutorialItem {
  @Prop tutorialItem: ArticleClass;

  build() {
    Row() {
      Column() {
        Text(this.tutorialItem.title)
          .height(19)
          .width('100%')
          .fontSize(14)
          .textAlign(TextAlign.Start)
          .textOverflow({ overflow: TextOverflow.Ellipsis })
          .maxLines(1)
          .fontWeight(400)
          .margin({ top: 4 })
        Text(this.tutorialItem.brief)
          .height(32)
          .width('100%')
          .fontSize(12)
          .textAlign(TextAlign.Start)
          .textOverflow({ overflow: TextOverflow.Ellipsis })
          .maxLines(2)
          .fontWeight(400)
          .fontColor('rgba(0, 0, 0, 0.6)')
          .margin({ top: 5 })
      }
      .height('100%')
      .layoutWeight(1)
      .alignItems(HorizontalAlign.Start)
      .margin({ right: 12 })

      Image(this.tutorialItem.imageSrc)
        .height(64)
        .width(108)
        .objectFit(ImageFit.Cover)
        .borderRadius(16)
    }
    .width('100%')
    .height(88)
    .borderRadius(16)
    .backgroundColor(Color.White)
    .padding(12)
    .alignItems(VerticalAlign.Top)
  }
}


@Component
struct EnablementItem {
  @Prop enablementItem: ArticleClass;

  build() {
    Column() {
      Image(this.enablementItem.imageSrc)
        .width('100%')
        .objectFit(ImageFit.Cover)
        .height(96)
        .borderRadius({
          topLeft: 16,
          topRight: 16
        })
      Text(this.enablementItem.title)
        .height(19)
        .width('100%')
        .fontSize(14)
        .textAlign(TextAlign.Start)
        .textOverflow({ overflow: TextOverflow.Ellipsis })
        .maxLines(1)
        .fontWeight(400)
        .padding({ left: 12, right: 12 })
        .margin({ top: 8 })
      Text(this.enablementItem.brief)
        .height(32)
        .width('100%')
        .fontSize(12)
        .textAlign(TextAlign.Start)
        .textOverflow({ overflow: TextOverflow.Ellipsis })
        .maxLines(2)
        .fontWeight(400)
        .fontColor('rgba(0, 0, 0, 0.6)')
        .padding({ left: 12, right: 12 })
        .margin({ top: 2 })
    }
    .width(160)
    .height(169)
    .borderRadius(16)
    .backgroundColor(Color.White)
  }
}



@Component
struct EnablementView {
  @State enablementList: Array<ArticleClass> = [
    new ArticleClass('1', $r('app.media.enablement_pic1'), 'HarmonyOS第一课',
      '基于真实的开发场景，提供向导式学习，多维度融合课程等内容，给开发者提供全新的学习体验。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-video-courses/video-tutorials-0000001443535745'),
    new ArticleClass('2', $r('app.media.enablement_pic2'), '开发指南',
      '提供系统能力概述、快速入门，用于指导开发者进行场景化的开发。指南涉及到的知识点包括必要的背景知识、符合开发者实际开发场景的操作任务流（开发流程、开发步骤、调测验证）以及常见问题等。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/application-dev-guide-0000001630265101'),
    new ArticleClass('3', $r('app.media.enablement_pic3'), '最佳实践',
      '针对新发布特性及热点特性提供详细的技术解析和开发最佳实践。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/topic-architecture-0000001678045510'),
    new ArticleClass('4', $r('app.media.enablement_pic4'), 'Codelabs',
      '以教学为目的的代码样例及详细的开发指导，帮助开发者一步步地完成指定场景的应用开发并掌握相关知识。Codelabs将最新的鸿蒙生态应用开发技术与典型场景结合，让开发者快速地掌握开发高质量应用的方法。同时支持互动式操作，通过文字、代码和效果联动为开发者带来更佳的学习体验。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-codelabs/codelabs-0000001443855957'),
    new ArticleClass('5', $r('app.media.enablement_pic5'), 'Sample',
      '面向不同类型的开发者提供的鸿蒙生态应用开发优秀实践，每个Sample Code都是一个可运行的工程，为开发者提供实例化的代码参考。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-samples/samples-0000001162414961'),
    new ArticleClass('6', $r('app.media.enablement_pic6'), 'API参考',
      '面向开发者提供鸿蒙系统开放接口的全集，供开发者了解具体接口使用方法。API参考详细地描述了每个接口的功能、使用限制、参数名、参数类型、参数含义、取值范围、权限、注意事项、错误码及返回值等。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-references/development-intro-0000001580026066'),
    new ArticleClass('7', $r('app.media.enablement_pic7'), 'FAQ',
      '开发者常见问题的总结，开发者可以通过FAQ更高效地解决常见问题。FAQ会持续刷新，及时呈现最新的常见问题。',
      'https://developer.huawei.com/consumer/cn/doc/harmonyos-faqs/faqs-development-0000001753952202'),
    new ArticleClass('8', $r('app.media.enablement_pic8'), '开发者论坛', '和其他应用开发者交流技术、共同进步。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
  ];

  build() {
    Column() {
      Text('赋能套件')
        .fontColor('#182431')
        .fontSize(16)
        .fontWeight(500)
        .fontFamily('HarmonyHeiTi-medium')
        .textAlign(TextAlign.Start)
        .padding({ left: 16 })
        .margin({ bottom: 8.5 })
      Grid() {
        ForEach(this.enablementList, (item: ArticleClass) => {
          GridItem() {
            EnablementItem({ enablementItem: item })
          }
        }, (item: ArticleClass) => item.id)
      }
      .rowsTemplate('1fr')
      .columnsGap(8)
      .scrollBar(BarState.Off)
      .height(169)
      .padding({ top: 2, left: 16, right: 16 })

    }
    .margin({ top: 18 })
    .alignItems(HorizontalAlign.Start)
  }
}


@Component
struct TutorialView {
  @State tutorialList: Array<ArticleClass> = [
    new ArticleClass('1', $r('app.media.tutorial_pic1'), 'Step1 环境的搭建',
      '本篇教程实现了快速入门——一个用于了解和学习HarmonyOS的应用程序。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('2', $r('app.media.tutorial_pic2'), 'Step2 使用Swiper构建运营广告位',
      'Swiper组件提供滑动轮播显示的能力。Swiper本身是一个容器组件，当设置了多个子组件后，可以对这些子组件进行轮播显示。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('3', $r('app.media.tutorial_pic3'), 'Step3 创建和组合视图',
      'Item定义子组件相关特征。相关组件支持使用条件渲染、循环渲染、懒加载等方式生成子组件。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('4', $r('app.media.tutorial_pic4'), 'Step4 网格和列表组建的使用',
      '网格和列表组件中，当Item达到一定数量，内容超过屏幕大小时，可以自动提供滚动功能，适合用于呈现同类数据类型或数据类型集',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('5', $r('app.media.tutorial_pic5'), 'Step5 应用架构设计基础——MVVM模式',
      'ArkUI采取MVVM = Model + View + ViewModel模式，将数据与视图绑定在一起，更新数据的时候直接更新视图。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('6', $r('app.media.tutorial_pic6'), 'Step6 应用架构设计基础——三层架构',
      '为了更好地适配复杂应用的开发，建议采用三层架构的方式对整个应用的功能进行模块化，实现高内聚、低耦合开发。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('7', $r('app.media.tutorial_pic7'), 'Step6 ArkWeb页面适配',
      'ArkWeb（方舟Web）提供了Web组件，用于在应用程序中显示Web页面内容，为开发者提供页面加载、页面交互、页面调试等能力。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('8', $r('app.media.tutorial_pic8'), 'Step7 数据驱动UI更新', '数据更新的同时会直接驱动UI的改变',
      'xxx'),
    new ArticleClass('9', $r('app.media.tutorial_pic9'), 'Step8 设置组件导航',
      'Navigation组件适用于模块内页面切换，一次开发，多端部署场景。通过组件级路由能力实现更加自然流畅的转场体验，并提供多种标题栏样式来呈现更好的标题和内容联动效果。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('10', $r('app.media.tutorial_pic10'), 'Step9 原生智能：AI语音朗读',
      '文本转语音服务提供将文本信息转换为语音并进行播报的能力，便于用户与设备进行互动，实现实时语音交互，文本播报。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('11', $r('app.media.tutorial_pic11'), 'Step10 原生互联：分布式流转',
      '流转能力打破设备界限，多设备联动，使用户应用程序可分可合、可流转，实现如邮件跨设备编辑、多设备协同健身、多屏游戏等分布式业务。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
    new ArticleClass('12', $r('app.media.tutorial_pic12'), 'Step11 一次开发，多端部署',
      '一套代码工程，一次开发上架，多端按需部署。支撑开发者快速高效的开发支持多种终端设备形态的应用，实现对不同设备兼容的同时，提供跨设备的流转、迁移和协同的分布式体验。',
      'https://developer.huawei.com/consumer/cn/forum/home?all=1'),
  ];

  build() {
    Column() {
      Text('入门教程')
        .fontColor('#182431')
        .fontSize(16)
        .fontWeight(500)
        .fontFamily('HarmonyHeiTi-medium')
        .textAlign(TextAlign.Start)
        .padding({ left: 16 })
        .margin({ bottom: 8.5 })
      List({ space: 12 }) {
        ForEach(this.tutorialList, (item: ArticleClass) => {
          ListItem() {
            TutorialItem({ tutorialItem: item })
          }
        }, (item: ArticleClass) => item.id)
      }
      .scrollBar(BarState.Off)
      .padding({ left: 16, right: 16 })
    }
    .margin({ top: 18 })
    .alignItems(HorizontalAlign.Start)
  }
}