HarmonyOS 鸿蒙Next中如何自定义上拉加载功能

可以参考一下下面的demo

import { PullToRefresh, PullToRefreshConfigurator } from '@ohos/pulltorefresh'

const tabsList = ["能源", "化工", "塑料", "化纤", "聚氨酯"]

@Entry
@Component
struct KeyboadPage {
  private refreshScroller: Scroller = new Scroller();
  private refreshConfigurator: PullToRefreshConfigurator = new PullToRefreshConfigurator();
  @State list: Array<string> =
    ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t"]

  @State listH: number = 0

  onPageShow(): void {
    this.listH = this.list.length * 50 + 50
  }

  build() {
    Column() {
      PullToRefresh({
        // 必传项，列表组件所绑定的数据
        data: $list,
        refreshConfigurator: this.refreshConfigurator,
        // 必传项，需绑定传入主体布局内的列表或宫格组件
        scroller: this.refreshScroller,
        // 必传项，自定义主体布局，内部有列表或宫格组件
        customList: () => {
          // 一个用@Builder修饰过的UI方法
          this.getListView();
        },
        // 可选项，下拉刷新回调
        onRefresh: () => {
          return new Promise<(resolve, reject) => {
            // 模拟网络请求操作，请求网络2秒后得到数据，通知组件，变更列表数据
            setTimeout(() => {
              resolve('刷新成功');
              console.info('刷新成功');
            }, 2000);
          });
        },

        // 可选项，上拉加载更多回调
        onLoadMore: () => {
          return new Promise<(resolve, reject) => {
            // 模拟网络请求操作，请求网络2秒后得到数据，通知组件，变更列表数据
            setTimeout(() => {
              resolve('');
              console.info('加载成功');
            }, 2000);
          });
        },
        customLoad: null,
        customRefresh: null,
      })
        .layoutWeight(1)

    }
  }

  @Builder
  getListView() {

    Column() {
      List({ scroller: this.refreshScroller }) {
        ListItem() {
          Text("第一条")
            .width("100%")
            .height(300)
            .backgroundColor(Color.Red)
        }

        ListItem() {
          Text("第二条")
            .width("100%")
            .height(500)
            .backgroundColor(Color.Yellow)
        }

        ListItem() {
          Text("第三条")
            .width("100%")
            .height(200)
            .backgroundColor(Color.Green)
        }
      }
      .edgeEffect(EdgeEffect.None)
      .nestedScroll({
        scrollForward: NestedScrollMode.PARENT_FIRST,
        scrollBackward: NestedScrollMode.SELF_FIRST
      })
    }
  }

  @Builder
  watchingTabBuilder(index: number, item: string) {
    Text(item)
      .fontSize(16)
      .fontColor("#121212")
      .padding({
        left: 15,
        right: 15,
        top: 12,
        bottom: 12
      })
      .borderRadius(5)
  }
}