xyzio

Sample code to return a PDF file to the browser in a Razor c# page using itext7.

using System;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Logging;
using iText.Kernel.Pdf;
using iText.Layout;
using iText.Layout.Element;
using System.IO;

public IActionResult OnPostManipulatePdf(String dest)
{
    MemoryStream ms = new MemoryStream();

    PdfWriter writer = new PdfWriter(ms);
    PdfDocument pdfDoc = new PdfDocument(writer);
    Document doc = new Document(pdfDoc);
    writer.SetCloseStream(false);

    Paragraph header = new Paragraph("header");

    doc.Add(header);
    doc.Close();

    byte[] byteInfo = ms.ToArray();
    ms.Write(byteInfo, 0, byteInfo.Length);
    ms.Position = 0;

    FileStreamResult fileStreamResult = new FileStreamResult(ms, "application/pdf");

    //Uncomment this to return the file as a download
    //fileStreamResult.FileDownloadName = "Output.pdf";

    return fileStreamResult;
}

Source:
https://stackoverflow.com/questions/1510451/how-to-return-pdf-to-browser-in-mvc