Asp.net core project with API project that uses swagger, and web project that uses angular 7. Setup to auto build the angular code. The project shows how u can pass the file name down in the header with the blob to angular httplclient and access it.

downloadPDF(file: any): any { const url = file;

return this.httpClient.get(url, { responseType: ResponseContentType.Blob, observe: 'response' })
  .pipe(
    tap(data => data,
      error => { }
    )
  );

}

Then access the header like this:

this.downloadPDF(fileLocation)
  .subscribe(res => {
    res.headers.get('filedownloadname'))
  });

Response.Headers.Add("FileDownloadName", response.FileDownloadName);

Response.Headers.Add("Access-Control-Expose-Headers", "filedownloadname");

as seen in the source code.