C# - How to convert an image to a PDF (using a free library) [closed]

Question

I've researched quite a bit but most answers I've found involve using iText which is only free for authors of open source software.

My question is how to utilise a free (preferably well maintained) PDF library to convert an image into PDF. More specifically I'm using Selenium to test a webpage and part of the requirements are for a screenshot of a results page to be saved in PDF format.

What I have at the moment:

        Screenshot screenshot = ((ITakesScreenshot)WebDriver).GetScreenshot();
        fileName =  filePath + fileName;

        screenshot.SaveAsFile($"{fileName}.png", ImageFormat.Png);

        // Convert to PDF and delete image
        // ?

Answer 1

I've come up with a way to do this using PDFSharp, hopefully will be useful for others as well.

        // Convert to PDF and delete image
        PdfHelper.Instance.SaveImageAsPdf($"{fileName}.png", $"{fileName}.pdf", 1000, true);

The new class:

using System.IO;
using PdfSharp.Drawing;
using PdfSharp.Pdf;  

public sealed class PdfHelper
{
    private PdfHelper()
    {
    }

    public static PdfHelper Instance { get; } = new PdfHelper();

    internal void SaveImageAsPdf(string imageFileName, string pdfFileName, int width = 600, bool deleteImage = false)
    {
        using (var document = new PdfDocument())
        {
            PdfPage page = document.AddPage();
            using (XImage img = XImage.FromFile(imageFileName))
            {
                // Calculate new height to keep image ratio
                var height = (int)(((double)width / (double)img.PixelWidth) * img.PixelHeight);

                // Change PDF Page size to match image
                page.Width = width;
                page.Height = height;

                XGraphics gfx = XGraphics.FromPdfPage(page);
                gfx.DrawImage(img, 0, 0, width, height);                
            }
            document.Save(pdfFileName);
        }

    if (deleteImage)            
        File.Delete(imageFileName);
    }
}