Question

I’m writing a web scraping program in C#. So far, I have been able to log in to website, save cookie, and return source code of another page. From this source code, I get a link that takes me to a pdf, but the page doesn’t end with .pdf extension. In the browser, this page shows the pdf image and there are controls in the browser including a save button.

I believe the pdf page was created with ColdFusion as it has .cfm, CFID and CFTOKEN in the URL.

How do I save this pdf file programmatically?

Two answers have suggested I save the binary stream to pdf. How do I get the binary data in the first place? I have tried the following:

        byte[] result;
        byte[] buffer = new byte[4096];

        WebRequest wr = WebRequest.Create(billURL);

        using (WebResponse response = wr.GetResponse())
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                using (MemoryStream memoryStream = new MemoryStream())
                {
                    int count = 0;
                    do
                    {
                        count = responseStream.Read(buffer, 0, buffer.Length);
                        memoryStream.Write(buffer, 0, count);

                    } while (count != 0);

                    result = memoryStream.ToArray();
                }
            }
        }

Do I then want to save result as a pdf, or am I doing something wrong there?

Answer 1

The common method in CF for streaming a PDF to the browser is using this method:

<cfheader name="Content-Disposition" value="attachment;filename=#PDFFileName#">
<cfcontent type="application/pdf" reset="true" variable="#toBinary(PDFinMemory)#">

Use a C# WebRequest to get the URL of the PDf. Then check the response header for a ‘Content-Type of ‘application/pdf’. If so, save the binary stream to a PDF file on disk.