'宣言 Function UseOptimizedGlyphRun( _ ByVal text As String, _ ByVal element As FrameworkElement, _ ByVal runProperties As TextRunProperties, _ ByVal paragraphProperties As TextParagraphProperties _ ) As Boolean
bool UseOptimizedGlyphRun( string text, FrameworkElement element, TextRunProperties runProperties, TextParagraphProperties paragraphProperties )
注: GlyphRuns は FormattedText より速いです。ただし、合字をサポートしません。