Font Substitution - PowerPoint C# API

Getting Font Substitution

To allow you find out the presentation fonts that are substituted during a presentation rendering process, Aspose.Slides provides the GetSubstitution method from the IFontsManager interface.

The C# code shows you how to get all the font substitutions that are performed when a presentation is rendered:

using (Presentation pres = new Presentation(@"Presentation.pptx"))
{
    foreach (var fontSubstitution in pres.FontsManager.GetSubstitutions())
    {
        Console.WriteLine("{0} -> {1}", fontSubstitution.OriginalFontName, fontSubstitution.SubstitutedFontName);
    }
}

Setting Font Substitution Rules

Aspose.Slides allows you to set rules for fonts that determines what must be done in certain conditions (for example, when a font cannot be accessed) this way:

1. Load the relevant presentation.
2. Load the font that will be replaced.
3. Load the new font.
4. Add a rule for the replacement.
5. Add the rule to the presentation font replacement rule collection.
6. Generate the slide image to observe the effect.

This C# code demonstrates the font substitution process:

// Loads a presentation
Presentation presentation = new Presentation("Fonts.pptx");

// Loads the source font that will be replaced
IFontData sourceFont = new FontData("SomeRareFont");

// Loads the new font
IFontData destFont = new FontData("Arial");

// Adds a font rule for font replacement
IFontSubstRule fontSubstRule = new FontSubstRule(sourceFont, destFont, FontSubstCondition.WhenInaccessible);

// Adds the rule to font substitute rules collection
IFontSubstRuleCollection fontSubstRuleCollection = new FontSubstRuleCollection();
fontSubstRuleCollection.Add(fontSubstRule);

// Adds the font rule collection to the rule list
presentation.FontsManager.FontSubstRuleList = fontSubstRuleCollection;

using (IImage image = presentation.Slides[0].GetImage(1f, 1f))
{
    // Saves the image to disk in the JPEG format
    image.Save("Thumbnail_out.jpg", ImageFormat.Jpeg);
}

NOTE

You may want to see Font Replacement.