如何使用Angular7在mobile上下载.pdf文件

我有一个组件,可以使用 FileSaver

export class MyComponent implements OnInit {

  public constructor( private myService: myService ) {}

  ngOnInit(): void {
      this.myService
          .downloadPdf() 
          .subscribe( (file: Blob) => {
               FileSaver.saveAs(file, 'fileName');
          });
  }
}

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';

@Injectable()
export class MyService {
  constructor(private http: HttpClient) { }

  downloadPdf() {
    const url = `somelinktothe.pdf`;
    return this.http.get(url, { responseType: 'blob' });
  }

}

从电脑上看一切都很好,但在移动设备上,它实际上是打开pdf文件而不是保存它。 我错过了什么?