【HarmonyOS Next开发】：ListItemGroup使用

export class CarItem {
  /**
   * 汽车名字集合*/
  public CarNameList: string[] = [];
  /**
   * 所属类型
   * */
  public Alphabet: string = '';
  constructor(carNameList: string[], alphabet: string) {
    this.CarNameList = carNameList;
    this.Alphabet = alphabet;
  }
}

import { CarItem } from "../Models/CarItem"
/**
 * 车辆交互类*/
export class CarViewModel {
  /**
   * 车辆详细信息集合
   * */
  public Items: CarItem[] = [];
  /**
   * 头字母集合*/
  public Alphabets: Array<string> = [];
  constructor() {
    //种子数据初始化
    this.Init();
  }
  /**
   * 初始化
   */
  public Init(): void {
    this.Items.push(new CarItem([
      "奥迪1",
      "奥迪2",
      "奥迪3",
      "奥迪4",
      "奥迪5",
      "奥迪6"
    ], "A"));
    this.Items.push(new CarItem([
      "奔驰1",
      "奔驰2",
      "奔驰3",
      "奔驰4",
      "奔驰5",
      "奔驰6",
      "奔驰7",
    ], "B"));
    this.Items.push(new CarItem([
      "凯美瑞1",
      "凯美瑞2",
      "凯美瑞3",
      "凯美瑞4",
      "凯美瑞5",
      "凯美瑞6",
      "凯美瑞7",
    ], "K"));
    this.Items.push(new CarItem([
      "玛莎拉蒂1",
      "玛莎拉蒂2",
      "玛莎拉蒂3",
      "玛莎拉蒂4",
      "玛莎拉蒂5",
      "玛莎拉蒂6",
      "玛莎拉蒂7",
    ], "M"));
    this.Alphabets.push('A');
    this.Alphabets.push('B');
    this.Alphabets.push('K');
    this.Alphabets.push('M');
  }
}

import { CarViewModel } from '../ViewModels/CarViewModel';
import { CarItem } from '../Models/CarItem'
@Entry
@Component
struct Index {
  /*
   *
   * 界面交互类*/
  @State CarVM: CarViewModel = new CarViewModel();
  @State SelectIndex: number = 0;
  listScroller: Scroller = new Scroller();
  /**
   * 头部控件样式
   */
  @Builder
  GroupHeader(alphabet: string) {
    Text(`${alphabet}`)
      .backgroundColor('#fff1f3f5')
      .width('100%')
      .padding(10)
  }
  build() {
    Column() {
      Stack({
        alignContent: Alignment.End
      }) {
        Column() {
          List({ scroller: this.listScroller }) {
            ForEach(this.CarVM.Items, (car: CarItem, index) => {
              ListItemGroup({
                header: this.GroupHeader(`${car.Alphabet}`)
              }) {
                ForEach(car.CarNameList, (name: string, carIndex) => {
                  ListItem() {
                    Text(`${name}`)
                      .fontSize(16)
                      .width('100%')
                      .padding(10)
                  }
                })
              }
            })
          }
          .height("100%")
          .onScrollIndex((selectIndex: number) => {
            //滑动时修改
            this.SelectIndex = selectIndex;
          })
          .sticky(StickyStyle.Header) //设置吸顶效果
        }.height('100%')
        //导航条
        AlphabetIndexer({
          arrayValue: this.CarVM.Alphabets,
          selected: this.SelectIndex
        })
          .onSelect((index) => {
            this.listScroller.scrollToIndex(index);
          })
      }
    }
    .width("100%")
    .height("100%")
  }
}