Question

I’m writing a windows service that’s required to retrieve data from a database, build a document from that data and then fax it. Tiff seems to be the standard for fax images and I know that I can encode an Image object as a tiff.

It would be great if I could build the image object like a document similar to how iTextSharp does it by creating new elements and attaching the elements to a PdfDocument object. My fax documents will be simple but require these things

• Centering a paragraph of text
• Add another image with absolute positioning (logo)
• Simple two column tables for field/value
• Horizontal rules

Creating an HTML document is trivial but .Net doesn’t seem to have a way to render HTML to an image object.

Desirable solutions would be some type of document class in the BCL that could be rendered to an image object where I could encode from there or some type of helper class/library or Image wrapper to draw these simple elements to an image instance.

Does either solution exist or is there maybe something else I could consider?

Answer 1

So I did find a solution that allows me to build documents with the features that I needed. I ended up using MigraDoc even though it definitely isn’t as elegant as iTextSharp. MigraDoc allowed me to create a System.Drawing.Image object from a Document object using its XGraphics class.

Using a few of the MigraDoc examples (I really wish they had better class library documentation, that was a big con IMHO) I was able to create a TIFF file like this

public void CreateNotificationImage(string imagePath, NotificationData data)
{
    // CreateDocument() is my own method where a new doc is created with new data
    Document doc = CreateDocument(data);
    doc.DefaultPageSetup.PageFormat = PageFormat.Letter;

    int page = 1;
    DocumentRenderer renderer = new DocumentRenderer(doc);
    renderer.PrepareDocument();
    PageInfo pageInfo = renderer.FormattedDocument.GetPageInfo(page);

    int dpi = 150;
    int dx  = (int)(pageInfo.Width.Inch * dpi);
    int dy  = (int)(pageInfo.Height.Inch * dpi);
    float scale = dpi / 72f;

    System.Drawing.Image image = new Bitmap(dx, dy, PixelFormat.Format32bppRgb);

    using (Graphics graphics = Graphics.FromImage(image))
    {
        graphics.Clear(System.Drawing.Color.White);
        graphics.ScaleTransform(scale, scale); // scale to 72dpi

        using (XGraphics gfx = XGraphics.FromGraphics(graphics, new XSize(Unit.FromInch(8.5).Point, Unit.FromInch(11).Point)))
        {
            renderer.RenderPage(gfx, page);
            WriteTiffImage(imagePath, image);
        }
    }           
}

WriteTiffImage() is used to encode the image as TIFF and then do the final write to disc.

private void WriteTiffImage(string targetPath, System.Drawing.Image image)
{
    Encoder        encoder  = Encoder.SaveFlag;
    ImageCodecInfo tiffInfo = ImageCodecInfo.GetImageEncoders()
                              .Where(e => e.MimeType == "image/tiff")
                              .FirstOrDefault();

    EncoderParameters encoderParams = new EncoderParameters(1);
    encoderParams.Param[0] = new EncoderParameter(encoder, (long)EncoderValue.MultiFrame);

    image.Save(targetPath, tiffInfo, encoderParams);

    // close file
    encoderParams.Param[0] = new EncoderParameter(encoder, (long)EncoderValue.Flush);
    image.SaveAdd(encoderParams);
}

I probably didn’t even need to do the scaling but it was in the example and worked out fine for what I wanted to accomplish.