SvgConversionOptions.FontResolver Property
Remarks
The default implementation will in first hand try to embed fonts as WOFF files, and if not possible, fallback to detecting standard fonts and assuming the client has those installed. You can implement a custom font resolver for e.g. using custom WOFF or WOFF2 files, or saving the embedded fonts as separate font files. files.
Built-in font resolvers:
| Resolver | Description |
|---|---|
| EmbedOpenType | Extracts fonts from the PDF, converts them to OpenType format, and then embed them as data URLs in the SVG. |
| EmbedWoff | Extracts fonts from the PDF, converts them to WOFF format, and then embed them as data URLs in the SVG. |
| LocalFonts | Tries to match the PDF fonts with commonly available fonts, and references them by name. |
Example
The following example will use LocalFonts to convert a PDF to SVG without embedding fonts into the extracted SVG. Instead local fonts assumed to be installed on the client machine are used.
var conversionOptions = new SvgConversionOptions { FontResolver = FontResolver.LocalFonts, }; using (var doc = PdfDocument.Open("input.pdf")) { var pageIndex = 0; foreach (var page in doc.Pages) { page.SaveAsSvg($"output-{pageIndex++}.svg", conversionOptions); } }
Custom behavior can be achieved by subclassing FontResolver and implementing the ResolveFont(SourceFont, CancellationToken) method. Here is a custom implementation using a locally installed Open Sans font.
class OpenSansFontResolver : FontResolver { public override Font ResolveFont(SourceFont sourceFont, CancellationToken cancellationToken) { var font = FontResolver.LocalFonts.ResolveFont(sourceFont, cancellationToken); if (sourceFont.Name != null && sourceFont.Name.Contains("OpenSans", StringComparison.InvariantCultureIgnoreCase) && font is LocalFont localFont) { font = new LocalFont("'Open Sans',sans-serif", localFont.FontWeight, localFont.FontStyle); } return font; } }
Types of substitute fonts that can be returned:
| Font type | Description |
|---|---|
| LocalFont | A font that is assumed to be installed on the machine viewing the SVG. |
| WebFont | Use a provided TrueType, OpenType, WOFF or WOFF2 font. Note that external resources are not allowed in standalone SVG files when displayed in browsers, so if you intend to use external SVG files, you need to return a WebFont instance using data URLs only. |
| InlinedFont | Inlines the glyphs from the font as paths and other elements within the SVG. This differs from WebFont, which are embedded as font files in the SVG. The inlined glyphs cannot be selected as text in the SVG. Currently only Type 3 fonts can be inlined, but more font types might be supported in the future. |