No appropriate font found using MigraDoc to create a PDF on Xamarin Forms

Question

I'm trying to create a pdf using MigraDoc. Here's a list of the libraries that I'm using:

• MigraDoc.DocumentObjectModel
• MigraDoc.DocumentObjectModel.Tables
• MigraDoc.Rendering

It throws me an error on printer.RenderDocument(). Code below

private async Task SavePDF()
        {
            filePath = emulatorFolderPath + "/Signed/" + _reportInformationViewModel.SelectedClient.Username + "-" + DateTime.Now.ToString("dd_MM_yyyy HH-mm") + ".pdf";
            MigraDocRendering.PdfDocumentRenderer printer = new MigraDocRendering.PdfDocumentRenderer
            {
                Document = document
            };
            printer.RenderDocument();
            printer.PdfDocument.Save(filePath);
        }

PS: I don't need to use a private font.

Answer 1

I've resolved by implementing IFontResolver I've added a folder Fonts that contains Open-Sans font. I've created a folder Helpers that contains a class called GenericFontResolver:

public class GenericFontResolver : IFontResolver
    {
        public string DefaultFontName => "OpenSans";

        public byte[] GetFont(string faceName)
        {
            if (faceName.Contains(DefaultFontName))
            {
                var assembly = typeof(ReportPreviewAndSignatureViewModel).GetTypeInfo().Assembly;
                var stream = assembly.GetManifestResourceStream($"PDFDemo.Fonts.{faceName}.ttf");

                using (var reader = new StreamReader(stream))
                {
                    var bytes = default(byte[]);

                    using (var ms = new MemoryStream())
                    {
                        reader.BaseStream.CopyTo(ms);
                        bytes = ms.ToArray();
                    }

                    return bytes;
                }
            }
            else
                return GetFont(DefaultFontName);
        }

        public FontResolverInfo ResolveTypeface(string familyName, bool isBold, bool isItalic)
        {
            var fontName = string.Empty;

            switch (familyName)
            {
                case "Open Sans":
                case "OpenSans":
                    fontName = "OpenSans";

                    if (isBold && isItalic)
                        fontName = $"{fontName}-BoldItalic";
                    else if (isBold)
                        fontName = $"{fontName}-Bold";
                    else if (isItalic)
                        fontName = $"{fontName}-Italic";
                    else
                        fontName = $"{fontName}-Regular";

                    return new FontResolverInfo(fontName);
                default:
                    break;
            }

            return null;
        }
    }

Then, on the constructor of the class that needs the font I've added:

GlobalFontSettings.FontResolver = new GenericFontResolver();

Then, when I'm creating the table you must add:

Style style = document.Styles["Normal"];
style.Font.Name = "OpenSans";