IHyphenationCallback interface

Implemented by classes which can register hyphenation dictionaries.

public interface IHyphenationCallback


RequestDictionary(string)Notifies application that hyphenation dictionary for the specified language wasn’t found and may need to be registered.


Shows how to open and register a dictionary from a file.

public void RegisterDictionary()
    // Set up a callback that tracks warnings that occur during hyphenation dictionary registration.
    WarningInfoCollection warningInfoCollection = new WarningInfoCollection();
    Hyphenation.WarningCallback = warningInfoCollection;

    // Register an English (US) hyphenation dictionary by stream.
    Stream dictionaryStream = new FileStream(MyDir + "hyph_en_US.dic", FileMode.Open);
    Hyphenation.RegisterDictionary("en-US", dictionaryStream);

    Assert.AreEqual(0, warningInfoCollection.Count);

    // Open a document with a locale that Microsoft Word may not hyphenate on an English machine, such as German.
    Document doc = new Document(MyDir + "German text.docx");

    // To hyphenate that document upon saving, we need a hyphenation dictionary for the "de-CH" language code.
    // This callback will handle the automatic request for that dictionary.
    Hyphenation.Callback = new CustomHyphenationDictionaryRegister();

    // When we save the document, German hyphenation will take effect.
    doc.Save(ArtifactsDir + "Hyphenation.RegisterDictionary.pdf");

    // This dictionary contains two identical patterns, which will trigger a warning.
    Assert.AreEqual(1, warningInfoCollection.Count);
    Assert.AreEqual(WarningType.MinorFormattingLoss, warningInfoCollection[0].WarningType);
    Assert.AreEqual(WarningSource.Layout, warningInfoCollection[0].Source);
    Assert.AreEqual("Hyphenation dictionary contains duplicate patterns. The only first found pattern will be used. " +
                    "Content can be wrapped differently.", warningInfoCollection[0].Description);

/// <summary>
/// Associates ISO language codes with local system filenames for hyphenation dictionary files.
/// </summary>
private class CustomHyphenationDictionaryRegister : IHyphenationCallback
    public CustomHyphenationDictionaryRegister()
        mHyphenationDictionaryFiles = new Dictionary<string, string>
            { "en-US", MyDir + "hyph_en_US.dic" },
            { "de-CH", MyDir + "hyph_de_CH.dic" }

    public void RequestDictionary(string language)
        Console.Write("Hyphenation dictionary requested: " + language);

        if (Hyphenation.IsDictionaryRegistered(language))
            Console.WriteLine(", is already registered.");

        if (mHyphenationDictionaryFiles.ContainsKey(language))
            Hyphenation.RegisterDictionary(language, mHyphenationDictionaryFiles[language]);
            Console.WriteLine(", successfully registered.");

        Console.WriteLine(", no respective dictionary file known by this Callback.");

    private readonly Dictionary<string, string> mHyphenationDictionaryFiles;

See Also