[c#] How to open PDF file in a new tab or window instead of downloading it (using asp.net)?

This is the code for downloading the file.

System.IO.FileStream fs = new System.IO.FileStream(Path+"\\"+fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
byte[] ar = new byte[(int)fs.Length];
fs.Read(ar, 0, (int)fs.Length);
fs.Close();

Response.AddHeader("content-disposition", "attachment;filename=" + AccNo+".pdf");
Response.ContentType = "application/octectstream";
Response.BinaryWrite(ar);
Response.End();

When this code is executed, it will ask user to open or save the file. Instead of this I need to open a new tab or window and display the file. How can I achieve this?

NOTE:

File won't necessary be located in the website folder. It might be located in an other folder.

this may help

Response.Write("<script>");
Response.Write("window.open('../Inventory/pages/printableads.pdf', '_newtab');");
Response.Write("</script>");

Here I am using iTextSharp dll for generating PDF file. I want to open PDF file instead of downloading it. So I am using below code which is working fine for me. Now pdf file is opening in browser ,now dowloading

        Document pdfDoc = new Document(PageSize.A4, 25, 10, 25, 10);
        PdfWriter pdfWriter = PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
        pdfDoc.Open();
        Paragraph Text = new Paragraph("Hi , This is Test Content");
        pdfDoc.Add(Text);
        pdfWriter.CloseStream = false;
        pdfDoc.Close();
        Response.Buffer = true;
        Response.ContentType = "application/pdf";
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.End();

If you want to download file, add below line, after this Response.ContentType = "application/pdf";

Response.AddHeader("content-disposition", "attachment;filename=Example.pdf");   

Instead of loading a stream into a byte array and writing it to the response stream, you should have a look at HttpResponse.TransmitFile

Response.ContentType = "Application/pdf";
Response.TransmitFile(pathtofile);

If you want the PDF to open in a new window you would have to open the downloading page in a new window, for example like this:

<a href="viewpdf.aspx" target="_blank">View PDF</a>

Response.ContentType = contentType;
HttpContext.Current.Response.AddHeader("Content-Disposition", "inline; filename=" + fileName);
Response.BinaryWrite(fileContent);

And

<asp:LinkButton OnClientClick="openInNewTab();" OnClick="CodeBehindMethod".../>

In javaScript:

<script type="text/javascript">
    function openInNewTab() {
        window.document.forms[0].target = '_blank'; 
        setTimeout(function () { window.document.forms[0].target = ''; }, 0);
    }
</script>

Take care to reset target, otherwise all other calls like Response.Redirect will open in a new tab, which might be not what you want.

you can return a FileResult from your MVC action.

*********************MVC action************

    public FileResult OpenPDF(parameters)
    {
       //code to fetch your pdf byte array
       return File(pdfBytes, "application/pdf");
    }

**************js**************

Use formpost to post your data to action

    var inputTag = '<input name="paramName" type="text" value="' + payloadString + '">';
    var form = document.createElement("form");
    jQuery(form).attr("id", "pdf-form").attr("name", "pdf-form").attr("class", "pdf-form").attr("target", "_blank");
    jQuery(form).attr("action", "/Controller/OpenPDF").attr("method", "post").attr("enctype", "multipart/form-data");
    jQuery(form).append(inputTag);
    document.body.appendChild(form);
    form.submit();
    document.body.removeChild(form);
    return false;

You need to create a form to post your data, append it your dom, post your data and remove the form your document body.

However, form post wouldn't post data to new tab only on EDGE browser. But a get request works as it's just opening new tab with a url containing query string for your action parameters.

Use this code. This works like a champ.

Process process = new Process();
process.StartInfo.UseShellExecute = true;
process.StartInfo.FileName = outputPdfFile;
process.Start();

You have to create either another page or generic handler with the code to generate your pdf. Then that event gets triggered and the person is redirected to that page.