Fonts
Unlike the .NET Framework and .NET (Target OS: Windows) version, the RadPdfProcessing's .NET Standard and .NET (Target OS: None) version does not offer a default mechanism for reading fonts. The FixedExtensibilityManager class is exposed to help implement this functionality.
Setting and Exporting Fonts
RadPdfProcessing needs access to the font data so that it can read it and add it to the PDF file. That is why, to allow the library to create and use fonts, you will need to provide an implementation of the FontsProviderBase abstract class and set this implementation to the FontsProvider property of the FixedExtensibilityManager.
You can find a detailed FixedExtensibilityManager and FontsProvider description and implementation in the How to implement a FontsProvider article.
If the FontsProvider property is not set, a default font will be used when exporting the document in cross-platform applications.
When converting a document (e.g., DOCX, HTML, etc.) to PDF format in .NET Standard and .NET (Target OS: None) projects, fonts from the original document are not automatically maintained in the PDF unless you explicitly provide the font data. This is especially important when the original document uses non-standard or custom fonts. The PdfProcessing library requires access to the actual font files to embed them in the PDF. If font data is not provided, the PDF model will substitute the missing fonts with standard ones, resulting in a mismatch between the original document and the exported PDF file.
Implementing a FontsProviderBase
public class FontsProvider : Telerik.Windows.Documents.Extensibility.FontsProviderBase
{
public override byte[] GetFontData(Telerik.Windows.Documents.Core.Fonts.FontProperties fontProperties)
{
string fontFileName = fontProperties.FontFamilyName + ".ttf";
string fontFolder = Environment.GetFolderPath(Environment.SpecialFolder.Fonts);
//The fonts can differ depending on the file
if (fontProperties.FontFamilyName == "Arial")
{
if (fontProperties.FontStyle == FontStyles.Italic && fontProperties.FontWeight == FontWeights.Bold)
{
fontFileName = $"arialbi.ttf";
}
else if (fontProperties.FontStyle == FontStyles.Italic)
{
fontFileName = $"ariali.ttf";
}
else if (fontProperties.FontWeight == FontWeights.Normal)
{
fontFileName = "arial.ttf";
}
else if (fontProperties.FontWeight == FontWeights.Bold)
{
fontFileName = $"arialbd.ttf";
}
}
//...add more fonts if needed...
DirectoryInfo directory = new DirectoryInfo(fontFolder);
FileInfo[] fontFiles = directory.GetFiles();
var fontFile = fontFiles.FirstOrDefault(f => f.Name.Equals(fontFileName, StringComparison.InvariantCultureIgnoreCase));
if (fontFile != null)
{
var targetPath = fontFile.FullName;
using (FileStream fileStream = File.OpenRead(targetPath))
{
using (MemoryStream memoryStream = new MemoryStream())
{
fileStream.CopyTo(memoryStream);
return memoryStream.ToArray();
}
}
}
return null;
}
}
Telerik.Windows.Documents.Extensibility.FontsProviderBase fontsProvider = new FontsProvider();
Telerik.Windows.Documents.Extensibility.FixedExtensibilityManager.FontsProvider = fontsProvider;