问在iframe中显示标题为“匿名”的PDF

EN

<iframe id="showPDFIframe" allowtransparency="false" title="TestPDF" width="100%" height="800" [attr.src]="dataLocalUrl" type="application/pdf"></iframe>

    pdfDownload: any;
    protected dataLocalUrl: SafeResourceUrl;
    
    ngOnInit() {
    this.requestOptions = this.createRequestOptions();
    this.requestOptions.responseType = ResponseContentType.Blob;
    this._pdfModelService.showPDF(this.requestOptions)
    .subscribe( (res) => {
      this.pdfDownload = res;
      this.dataLocalUrl = this.domSanitizer.bypassSecurityTrustResourceUrl(window.URL.createObjectURL(res));
    }, err => {
      console.log(err);
    })
   }

showPDF(options?: RequestOptions): any {
    return this._http.get(this.endpoints.showPDF.uri, options)
      .map( (res) => {
        return new Blob([res], { type: 'application/pdf' })
      });
  }