如何在Angular Typescript

Question

我正在尝试制作有角度的页面并使用打字稿，并且我正在使用日期选择器选择日期，后端方法正在等待参数为LocalDate

sendStartDateChangeEmail(updateData: { employeeId: number, selectedDate: string }) {
    const requestParams = new HttpParams().append('requestedStartDate', updateData.selectedDate);
    return this._http.post(`/request-start-date-change/` + updateData.employeeId, null, {params: requestParams})
      .map((response: any) => {
      if (response['success'] !== true) {
        throw Observable.throw(response['errorMessage']);
      }
      return response;
    });
  }

如上所示，updateData.selectedDate是一个字符串，在后端方法中，日期接受为LocalDate而不是字符串。

public ResponseEntity<Boolean> sendStartDateChangeRequest(@PathVariable(name = "employeeId") long employeeId,
                                                           @RequestParam(name = "requestedStartDate") LocalDate requestedStartDate)

如何在前端将变量分配为LocalDate？