当angular加载json数据时如何添加加载器？

import { Component, OnInit } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-example',
  template: `
    <div *ngIf="isLoading">加载中...</div>
    <div *ngIf="!isLoading">
      <!-- 显示加载完成后的数据 -->
      {{ jsonData }}
    </div>
  `,
})
export class ExampleComponent implements OnInit {
  isLoading: boolean = false;
  jsonData: any;

  constructor(private http: HttpClient) {}

  ngOnInit() {
    this.isLoading = true;

    this.http.get('path/to/json/data').subscribe(
      (data) => {
        this.jsonData = data;
        this.isLoading = false;
      },
      (error) => {
        console.error('数据加载失败：', error);
        this.isLoading = false;
      }
    );
  }
}