mvcrazortopdf Null Reference Exception on first click ASP.NEt (Session not retrieving properly)

Question

Im working on a program that downloads a pdf file using mvcrazortopdf. On the first click, it throws a NullReferenceException error. Here is my code:

Controller:(ReviewerController.cs)

    public ActionResult PicOrderPDF() //error on this line
    {
        PurchaseOrder req = (PurchaseOrder)Session["purchaseOrderData"];
        var date = String.Format("{0:yyyyMMdd}", DateTime.Now);

        return new PdfActionResult(req)
        {
            FileDownloadName = date + "-PurchaseOrder" + (req.PicID).ToString("D4") + ".pdf"
        };

    }
    [HttpPost]
    public ActionResult DownloadPdf(PurchaseOrder purchaseOrder)
    {
        Session["purchaseOrderData"] = purchaseOrder;
        return RedirectToAction("PicOrderPDF", "Reviewer");

    }

Model: (PurchaseOrder.cs)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace SampleProject.Models
{
    public class PurchaseOrder : Account
    {

       public int PicID { get; set; }
       public DateTime RequiredDate { get; set; }

    }
}

PicOrderPDF is the view of the pdf to be downloaded. I tried adding a breakpoint at the error line to check and turns out req is null.But after continuing and clicking download again, it downloads just fine. Sorry im new at this

Is `req` null because there isn't any session item called `purchaseOrderData`? — Nate Barbettini, May 13 '17 at 01:37
Try to retrieve purchaseOrder from session just after adding it to session in DownloadPdf action and check if it is null? — Chetan, May 13 '17 at 02:03
@ChetanRanpariya should i retrieve it in DownloadPdf or in PicOrderPDF? — desperateStudent, May 13 '17 at 02:16
@desperateStudent you mean when you go directly to PicOrderPDF it throws exception or when you go from DownloadPdf? — Usman, May 13 '17 at 02:37
@Usman the null exception is on the PicOrderPDF particularly in the `PdfActionResult` — desperateStudent, May 13 '17 at 03:47
When you go to picorderpdf before download pdf it will throw exception because the session will be null — Usman, May 13 '17 at 03:50
@Usman sorry im new to this. Would you suggest removing the `[HttpPost]` and go to `DownloadPDF`first then `PicOrderPDF` — desperateStudent, May 13 '17 at 04:47
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/144107/discussion-between-usman-and-desperatestudent). — Usman, May 13 '17 at 04:59

score 1 · Accepted Answer · edited May 23 '17 at 12:03

1

the problem was the first time the session was cleared which resolved with adding

protected void Session_Start()
 {

 }

in the Global.asax.cs you can also check this session variables lost between controllers action methods

edited May 23 '17 at 12:03

Community

1
1

answered May 13 '17 at 06:20

Usman

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"Server Error in '/' Application." – desperateStudent May 13 '17 at 06:35
Are you sure `req` is not null ? – Chetan May 15 '17 at 01:36
OMG it worked, Thank you @Usman!! – desperateStudent May 15 '17 at 02:39

mvcrazortopdf Null Reference Exception on first click ASP.NEt (Session not retrieving properly)

1 Answers1