CODEWITHSUNDEEP
asp.netpdfreportviewerresponse
Quad Coders
Quad Coders

Reputation: 668

Render multiple PDF to browser with Report VIewer - ASP.NET

Current situation

I have ASP.NET web application that render PDF for users using MS Report Viewer. The PDF is rendered with this method:

    Byte pdfByte = Byte();
    pdfByte = ReportViewer.LocalReport.Render("PDF", Nothing, mimeType, encoding, extensions, stream, warning)

And send to browser as an attachment with response object:

    Response.Clear()
    Response.ContentType = mimeType
    Response.AddHeader("content-disposition", "attachment; filename=myfile." + extension)
    Response.BinaryWrite(pdfByte)
    Response.Flush()
    Response.End()

This work great! The user browser will get the PDF as download-able attachment.

What I am trying to achieve

Render multiple PDF and send all of them separately to user's browser. User will get separate PDF documents. It doesn't matter whether they will get them all at once or one by one.

The problem

The problem is after Response.End() the next line of code is not executed. I have tried to store the pdfByte object in session, looping through it and send them to user's browser with Response object but after the first PDF get sent then it stop. I have also tried removing Response.End() thinking the code will keep running but still it stop after the first PDF get sent.

Please advice any workaround or tips. Thanks!

Upvotes: 2

Views: 3948

Answers (2)

matk
matk

Reputation: 1518

Admittedly the method I'm using doesn't feel very elegant, but here's what I'm doing:

  • create one IFRAME on the page for each document you want to send to the client (maybe create the IFRAMEs dynamically in server-side code if the number of documents is variable);

  • create a HttpHandler that generates the PDF documents, depending on a parameter you're passing in through the QueryString, just like you're doing above;

  • set the src on all IFRAMES to the URL of the HttpHandler with the appropriate parameters attached.

Of course the HttpHandler needs to do implement security logic, if required.

This works quite beautifully: If I want to send 3 documents, I create 3 IFRAMEs, set their src, and the user will see 3 "Save As..." dialogs pop up.

Upvotes: 1

VinayC
VinayC

Reputation: 49195

You cannot send multiple files (as separate entities) in a single HTTP response (the protocol does not support it. However, what you can do is to archive all files together and send the that single zip (or whatever format you want) to the client.

You can use libraries such as DotNetZip/SharpZipLib to combine (and compress) files together. Based on library API, you may need to save PDF files to disk before adding to zip file. Also do not forget to change your content type appropriate while sending the zip file to client.

Yet another alternative is to provide user with a page having multiple links to download files. It may mean that you either have to store your PDFs for some time so that they can served later (via links) or make link point to a handler that will re-run the report again to get the PDF out of it.

Upvotes: 2

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