HarmonyOS 是否有区号选择示例

class Contacts {
  constructor(index: string, names: string[]) {
    this.index = index
    this.names = names
  }
  index: string // 序号
  names: string[] // 姓名组
}
@Entry
@Component
struct Index {
  @State contacts: Contacts[] = [
    new Contacts('A', ["xxx", "xxx", "xxx"]),
    new Contacts('B', ["xxx", "xxx", "xxx"]),
    new Contacts('C', ["xxx", "xxx", "xxx"]),
    new Contacts('D', ["xxx", "xxx", "xxx"]),
    new Contacts('E', ["xxx", "xxx"]),
    new Contacts('F', ["xxx", "xxx"]),
    new Contacts('G', ["xxx", "xxx", "xxx"]),
    new Contacts('H', ["xxx", "xxx", "xxx"]),
  ]
  scroller: Scroller = new Scroller() // list 滚动控制
  value: string[] = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H']
  @State flag: number = 0 // 绑定AlphabetIndexer的index
  preIndex: number = 0;

  build() {
    Row() {
      List({ space: 20, initialIndex: 0, scroller: this.scroller }) {
        ForEach(this.contacts, (value: Contacts) => {
          ListItem() {
            Column() {
              Text('' + value.index)
                .fontSize(30)
                .textAlign(TextAlign.Center)
                .backgroundColor('#ffffff')
                .margin(30)
              ForEach(value.names, (name: string) => {
                Column({ space: 10 }) {
                  Text('' + name)
                    .fontSize(20)
                    .textAlign(TextAlign.Center)
                    .backgroundColor('#ffffff')
                    .margin(10)
                }
              })
            }
          }
        })
      }
      .width('80%')
      .backgroundColor('#fffff0')
      .listDirection(Axis.Vertical)
      .onScrollIndex((firstIndex: number, lastIndex: number) => {
        this.flag = firstIndex // 刷新 AlphabetIndexer
      })
      AlphabetIndexer({ arrayValue: this.value, selected: this.flag })
        .width("20%")
        .font({ size: 20, weight: FontWeight.Bold })
        .selectedColor(Color.Blue)
        .selectedBackgroundColor(0xCCCCCC)
        .usingPopup(true)// 是否显示弹出框
        .selectedFont({ size: 28, weight: FontWeight.Bolder })
        .itemSize(30)
        .alignStyle(IndexerAlign.Left)
        .onSelect((index: number) => {
          console.info(`AlphabetIndexer 选中了 ${this.value[index]}`)
          for (let i = 0; i < this.contacts.length; i++) {
            if (this.contacts[i].index.toString() === this.value[index]) {
              this.preIndex = index;
              this.scroller.scrollToIndex(i);
              return;
            }
          }
          this.flag = this.preIndex;
        })
    }.width("100%")
  }
}