如何在Angular模板中从后台获取dropdownlist的值

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
importimport { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class DataService {
  constructor(private http: HttpClient) { }

  getDropdownListData(): Observable<any> {
    return this.http.get<any>('后台API地址');
  }
}

import { Component, OnInit } from '@angular/core';
import { DataService } from '路径/data.service';

@Component({
  selector: 'app-dropdownlist',
  templateUrl: './dropdownlist.component.html',
  styleUrls: ['./dropdownlist.component.css']
})
export class DropdownlistComponent implements OnInit {
  dropdownListData: any[];

  constructor(private dataService: DataService) { }

  ngOnInit(): void {
    this.dataService.getDropdownListData().subscribe(data => {
      this.dropdownListData = data;
    });
  }
}

<select>
  <option *ngFor="let item of dropdownListData" [ngValue]="item.value">{{ item.label }}</option>
</select>