Generate PDF in server (Asp.Net Core) and retrieve in Browser (Angular)

Question

I'm using Asp.Net Core and ItextSharp to generate a PDF report and sending to the Browser.

[HttpGet]
public async Task<IActionResult> GetStream(string ids)
{
  try
        {
            List<int> labRequestIds = JsonConvert.DeserializeObject<List<int>>(requestIds);
            MemoryStream ms = new MemoryStream();
            Document doc = new Document(PageSize.A4, 30f, 30f, 30f, 30f);
            PdfWriter writer = PdfWriter.GetInstance(doc, ms);
            doc.Open();
            await CreatePlateDoc(labRequestIds, doc);
            doc.Close();
            writer.Flush();
            ms.Seek(0, SeekOrigin.Begin);
            return File(ms, "application/pdf");
         }
}

Then using angular (typescript) I get the response in the browser like that: Service:

getStream(requestIds: Array<number>) {
    return new Promise((resolve, reject) => {
        this.http.get(AppConfig.LrmApiUrl + '/fileGenerator/plates'
            + '?requestIds=' + JSON.stringify(requestIds)
            , { headers: this.authService.getHeaders() })
            .subscribe((data:any) => {
                console.log(data);
                if (data) {
                    resolve(data._body);
                }                 
            },
            err => reject(Tools.handleResponseError(err))
        );
    });
}

and in the controller try to download the PDF created with Filesaver.js like that:

downloadClick() {      
    this._fileGeneratorService.getPlateStream(this.selectedRequestIds)
        .then(data => {
            let saveAs = require('file-saver');
            let name = this.selectedRequests.map(function (x) {
                return x.code;
            }).join();
            let blob = new Blob([data], { type: 'application/pdf });
            saveAs(blob, name);
        })
        .catch(err => console.log(err));
}

But it is not working. The pdf downloaded is empty but has information on it.

Answer 1

At the end I solved it like that:

  public async Task<IActionResult> CreatePlatePdf(string dto)
    {
        try
        {
            List<int> dto= JsonConvert.DeserializeObject<List<int>>(dto);
            MemoryStream ms = new MemoryStream();
            Document doc = new Document(PageSize.A4, 30f, 30f, 30f, 30f);
            PdfWriter writer = PdfWriter.GetInstance(doc, ms);

            doc.Open();
            await this.CreateDoc(dto, doc);
            doc.Close();
            writer.Flush();
            byte[] byteInfo = ms.ToArray();
            ms.Write(byteInfo, 0, byteInfo.Length);
            ms.Seek(0, SeekOrigin.Begin);
            return this.File(ms, "application/pdf", fileName.pdf);
        }
}

and calling it in the client like that:

downloadPlatesClick() 
{
    window.location.href = url_pdf;
}

So right now the only problem that I have is that you can call it without authorization. So anyone knows how to add an authorization (header) in the calling of my srvice?¿