HarmonyOS 鸿蒙Next 使用contact追加二维数组，UI没变化

参考此demo:

[@Observed](/user/Observed)
export class Employee {
  useId: string = “”
}
@Observed
export class EmployeeList {
  employeeList: Employee[] = []
}
@Observed
export class EmployeeListResponse {
  orgUserList: EmployeeList[] = []
}
@Entry
@Component
struct Index {
  @State employeeData: EmployeeListResponse = {
    orgUserList: [
      {employeeList:[{useId:“1”}, {useId:“2”}, {useId:“3”}]},
      {employeeList:[{useId:“41”}, {useId:“42”}, {useId:“43”},]},
      {employeeList:[{useId:“51”}, {useId:“52”}, {useId:“53”},]},
    ]
  }
  build() {
    Column() {
      Button(“添加”).onClick(() => {
        this.employeeData.orgUserList = this.employeeData.orgUserList.concat([ {employeeList:[{useId:“3”}, {useId:“6”}, {useId:“9”}]},])
      })
      ForEach(this.employeeData.orgUserList, (item: EmployeeList, index) => {
        ForEach(item.employeeList, (el: Employee, childIndex) => {
          Text(el.useId)
        })
      })
    }
    .height(‘100%’)
    .width(‘100%’)
  }
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

onReachEnd：List边缘效果为弹簧效果时，划动经过末尾位置时触发一次，回弹回末尾位置时再触发一次。

onReachStart：List初始化时如果initialIndex为0会触发一次，List滚动到起始位置时触发一次。List边缘效果为弹簧效果时，划动经过起始位置时触发一次，回弹回起始位置时再触发一次。

List边缘效果默认值就是spring弹簧模式，所以会触发两次