鸿蒙HarmonyOS从零实现类微信app效果——基础界面搭建

export class BottomNavigationEntity {
  /**
   * 底部导航tab标题
   */
  title: Resource;

  /**
   * 底部导航tab图片
   */
  image: Resource;

  /**
   * 底部导航tab图片，未选中
   */
  unCheckImage: Resource;

  /**
   * tab类型标志位
   */
  tag: number;

  constructor(tag: number, title: Resource, image: Resource, unCheckImage: Resource) {
    this.tag = tag;
    this.title = title;
    this.image = image;
    this.unCheckImage = unCheckImage;
  }
}

@Preview  # 方便单个view直接预览
@Component  # 标记是一个组件，可供其他组件引用
export default struct BottomNavigationItem {
  private navigationItem: BottomNavigationEntity;
  
  # 这里的Link是用于父组件和子组件进行通信	
  @Link currentIndex: number;

  build() {
    Column({ space: 5 }) {
    # 这里判断如果当前选中的item是当前的这个，则使用选中状态图片
      Image(this.currentIndex === this.navigationItem.tag ? this.navigationItem.image : this.navigationItem.unCheckImage)
        .width(24)
        .height(24)
      Text(this.navigationItem.title)
        .fontSize(14)
        .fontColor(this.currentIndex === this.navigationItem.tag ? Color.Green : 0x333333)
    }
  }
}

@Preview
@Component
export default struct BottomNavigation {
  @Link currentItemIndex: number;

  build() {
    Row({ space: 5 }) {
      //  这里通过对结合遍历，生成BottomNavigationItem进行填充BottomNavigation
      ForEach(navigationViewModel.getNavigationList(), (item: BottomNavigationEntity, index: number) => {
        # 对于这里的$currentItemIndex写法可以先将疑问留着，后续结合Link一并说明
        BottomNavigationItem({ navigationItem: item, currentIndex: $currentItemIndex })
          .onClick(() => {
          	#  点击后更新选中的item，以实现刷新界面的效果
            this.currentItemIndex = index
          })
      })
    }
    .width('100%')
    .height(65)
    .padding({
      top: 5,
      bottom: 5
    })
    .justifyContent(FlexAlign.SpaceAround)
    .backgroundColor(0xF3EEEA)
  }
}

@Entry
@Component
struct WechatMainFrame {
  @State currentCheckIndex: number = 0;

  build() {
    RelativeContainer() {
      BottomNavigation({ currentItemIndex: $currentCheckIndex })
        .alignRules({
          bottom: { anchor: "__container__", align: VerticalAlign.Bottom },
          left: { anchor: "__container__", align: HorizontalAlign.Start }
        })
        .id("bottomNavigation")

      Stack() {
        HomeFragment().visibility(this.currentCheckIndex == 0 ? Visibility.Visible : Visibility.Hidden)
        ContactFragment().visibility(this.currentCheckIndex == 1 ? Visibility.Visible : Visibility.Hidden)
        DiscoverFragment().visibility(this.currentCheckIndex == 2 ? Visibility.Visible : Visibility.Hidden)
        MeFragment().visibility(this.currentCheckIndex == 3 ? Visibility.Visible : Visibility.Hidden)
      }
      .width('100%')
      .height('100%')
      .alignRules({
        left: { anchor: "__container__", align: HorizontalAlign.Start },
        right: { anchor: "__container__", align: HorizontalAlign.End },
        bottom: { anchor: "bottomNavigation", align: VerticalAlign.Top },
        top: { anchor: "__container__", align: VerticalAlign.Top }
      })
      .id("contentPanel")
    }
    .width('100%').height('100%')
  }
}

export default class EntryAbility extends UIAbility {
  ...
  onWindowStageCreate(windowStage: window.WindowStage) {
    // Main window is created, set main page for this ability
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');

    windowStage.loadContent('pages/WechatMainFrame', (err, data) => {
      if (err.code) {
        hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
        return;
      }
      hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
    });
  }
  ...