Generate PDF from ASP.NET from raw HTML/CSS content?

Question

I'm sending emails that have invoices attached as PDFs. I'm already - elsewhere in the application - creating the invoices in an .aspx page. I'd like to use Server.Execute to return the output HTML and generate a PDF from that. Otherwise, I'd have to use a reporting tool to "draw" the invoice on a PDF. That blows for lots of reasons, not the least of which is that I'd have to update both the .aspx page and the report for every minor change. What to do...

Answer 1

There is no way to generate a PDF from an HTML string directly within .NET, but there are number of third party controls that work well.

I've had success with this one: http://www.html-to-pdf.net and this: http://www.htmltopdfasp.net

The important questions to ask are:

1. Does it render correctly as compared to the 3 major browsers: IE, FF and Safari/Chrome?
2. Does it handle CSS fine?
3. Does the control have it's own rendering engine? If so, bounce it. You don't want to trust a home grown rendering engine - the browsers have a hard enough problem getting everything pixel perfect.
4. What dependencies does the third party control require? The fewer, the better.

There are a few others but they deal with ActiveX displays and such.

Answer 2

We use a product called ABCPDF for this and it works fantastic.

http://www.websupergoo.com/abcpdf-1.htm

Answer 3

wkhtmltopdf is a free and cool exe to generate pdf from html. Its written in c++. But nReco htmltopdf is a wrapper dotnet library for this awesome tool. I implemented using this dotnet library and it was just so good it does everything by its own you just need to give html as a data source.

/// <summary>
/// Converts html into PDF using nReco dll and wkhtmltopdf.exe.
/// </summary>       
private byte[] ConvertHtmlToPDF()
{
  HtmlToPdfConverter nRecohtmltoPdfObj = new HtmlToPdfConverter();
  nRecohtmltoPdfObj.Orientation = PageOrientation.Portrait;
  nRecohtmltoPdfObj.PageFooterHtml = CreatePDFFooter();
  nRecohtmltoPdfObj.CustomWkHtmlArgs = "--margin-top 35 --header-spacing 0 --margin-left 0 --margin-right 0";           
  return nRecohtmltoPdfObj.GeneratePdf(CreatePDFScript() + ShowHtml() + "</body></html>");
}

The above function is an excerpt from the below link post which explains it in detail. HTML to PDF in ASP.Net

Answer 4

The initial question is about converting another aspx page containing an invoice to a PDF document. The invoice is probably using some session data and the user suggests to use Server.Execute() to obtain the invoice page HTML code and then to convert that code to PDF. Converting the invoice page URL directly is not possible because a new session would be created during conversion and the session data would be lost.

This is actually a good technique to preserve session data during conversion which is applied in Convert a HTML Page to PDF in Same Session ASP.NET Demo of the EvoPdf library. The complete C# code to get the HTML string rendered by the invoice page and to convert that string to PDF is:

// Execute the invoice page and get the HTML string rendered by this page
TextWriter outTextWriter = new StringWriter();
Server.Execute("Invoice.aspx", outTextWriter);

string htmlStringToConvert = outTextWriter.ToString();

// Create a HTML to PDF converter object with default settings
HtmlToPdfConverter htmlToPdfConverter = new HtmlToPdfConverter();

// Use the current page URL as base URL
string baseUrl = HttpContext.Current.Request.Url.AbsoluteUri;

// Convert the page HTML string to a PDF document in a memory buffer
byte[] outPdfBuffer = htmlToPdfConverter.ConvertHtml(htmlStringToConvert, baseUrl);

// Send the PDF as response to browser

// Set response content type
Response.AddHeader("Content-Type", "application/pdf");

// Instruct the browser to open the PDF file as an attachment or inline
Response.AddHeader("Content-Disposition", String.Format("attachment; filename=Convert_Page_in_Same_Session.pdf; size={0}", outPdfBuffer.Length.ToString()));

// Write the PDF document buffer to HTTP response
Response.BinaryWrite(outPdfBuffer);

// End the HTTP response and stop the current page processing
Response.End();

Answer 5

This sounds like a job for Prince. It can take HTML and CSS and generate a PDF, which you can then present to your users. It supports CSS3 better than most web browsers (staff include Håkon Wium Lie, the inventor of CSS).

See the samples, especially the ones for Wikipedia pages, for the beautiful output it can generate. There's also an interesting Google Tech Talk with the authors.

Edit: There is a .NET wrapper available.

Answer 6

If you try to find some html to pdf software via GOOGLE you'll get a pile of this stuff. There are about 10 leaders but most of them use IE dlls in background mode. Just couple of them use their own parsing engine. Please try PDF Duo .NET component in your ASP.NET project if you wish to create a PDF programaticaly. It is light component for a cool generating of PDF invoces, reports e.g.

Answer 7

As long as you can make sure to use proper XHTML, you could also use a product like Alt-Soft's Xml2PDF to convert XML (XHTML) into PDF by means of XSLT/XSL-FO.

It takes a bit of a learning curve to master, but it works very well once you've "got" it!

Marc

Answer 8

Since you are producing the answer, you can use a tool like Report.NET: http://sourceforge.net/projects/report/

I disagree with the answers that say you cannot convert directly from output to PDF, however, as you can "re-call" the page and get the HTML as a stream and convert it. I am not sure what tool you would want to use to do this, however. In other words, it is possible, but I am not sure it is worth it. The PDF creation libs, like Report.NET, even though they force reusing some logic and no automagic converrsion, it is easier.

I have not tried this component, but I have heard good things about it from those who have. The model is more like HTML, but I am not sure you can simply send a rendered ASPX to it to create PDF: http://www.websupergoo.com/abcpdf-8.htm

Answer 9

A possible minimal solution to use Server.Execute() to obtain the HTML of the invoice page and convert that code to a PDF using winnovative html to pdf api for .net is:

TextWriter outTextWriter = new StringWriter();
Server.Execute("Invoice.aspx", outTextWriter);

HtmlToPdfConverter htmlToPdfConverter = new HtmlToPdfConverter();

byte[] pdfBytes = htmlToPdfConverter.ConvertHtml(outTextWriter.ToString(),
            httpContext.Current.Request.Url.AbsoluteUri);

Answer 10

You can use PDFSharp or iTextSharp to convert html to pdf. PDFSharp is not free.

Answer 11

I'd go a different route. Assuming you are using SQL Server, use SSRS and generate the PDF that way.