Spell-Checking

Most rich editors implement two types of spell-checking:

Modal spell checking: Shows the Spelling dialog box and selects each spelling mistake in the document. The user may choose to ignore the mistake, fix it by typing or picking from a list of suggestions, or add the word to a user dictionary.
As-you-type checking: Highlights spelling mistakes as the user types, typically with a wavy red underline. The user may right-click the mistake in the document to see a menu with options that include ignore, add to dictionary, or pick a suggestion to correct the mistake automatically.

RichTextBox supports both types of spell-checking using the C1SpellChecker component, included in WPF Edition. Please note that the C1SpellChecker ships as a separate assembly altogether because it can be used with various other controls for spell-checking.

To implement modal spell checking, you need to add a reference to the C1.WPF.SpellChecker assembly to your project. Then, add the following code to your project. This code creates a new C1SpellChecker object to be shared by all controls on the page that require spell-checking. Later, the page constructor invokes the Load method to load the main spelling dictionary from a stream containing the compressed Dictionary data. C1SpellChecker includes over 20 other dictionaries which can be downloaded from our site. In this case, we are loading C1Spell_en-US.dct, the American English dictionary. This file must be present on the application folder. When the modal checking is complete, the _c1SpellChecker_CheckControlCompleted event fires and shows a dialog box to indicate that the spell-checking operation is complete.

spellchecker used with richtextbox

public partial class SpellCheckerRichTextBoxDemo : UserControl
    {
        // declare the C1SpellChecker
        C1SpellChecker _c1SpellChecker = new C1SpellChecker();
        public SpellCheckerRichTextBoxDemo()
        {
            InitializeComponent();
            this.Tag = Properties.Resources.SpellCheckerRtbDemoDescription;
            Loaded += Page_Loaded;
            Unloaded += Page_Unloaded;
        }
        void Page_Loaded(object sender, RoutedEventArgs e)
        {
            // connect toolbar to C1RichTextBox
            _rtbToolbar.RichTextBox = _richTextBox;
            _richTextBox.SpellChecker = _c1SpellChecker;
            // load sample text into text boxes
            using (var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("SpellCheckerExplorer.Resources.test.txt"))
            using (var sr = new StreamReader(stream))
            {
                var text = sr.ReadToEnd();
                _richTextBox.Text = text;
            }
            // set up ignore list
            WordList il = _c1SpellChecker.IgnoreList;
            il.Add("ComponentOne");
            il.Add("Silverlight");
            // monitor events
            _c1SpellChecker.BadWordFound += _c1SpellChecker_BadWordFound;
            _c1SpellChecker.CheckControlCompleted += _c1SpellChecker_CheckControlCompleted;
            // load main dictionary
            if (_c1SpellChecker.MainDictionary.State != DictionaryState.Loaded)
                _c1SpellChecker.MainDictionary.Load(Application.GetResourceStream(new Uri("/" + new AssemblyName(Assembly.GetExecutingAssembly().FullName).Name + ";component/Resources/C1Spell_en-US.dct", UriKind.Relative)).Stream);
            if (_c1SpellChecker.MainDictionary.State == DictionaryState.Loaded)
            {
                WriteLine("loaded main dictionary ({0:n0} words).", _c1SpellChecker.MainDictionary.WordCount);
            }
            else
            {
                WriteLine("failed to load dictionary: {0}", _c1SpellChecker.MainDictionary.State);                    
            }
            // save user dictionary when app exits
            App.Current.Exit += App_Exit;
        }
        void Page_Unloaded(object sender, RoutedEventArgs e)
        {
            _c1SpellChecker.BadWordFound -= _c1SpellChecker_BadWordFound;
            _c1SpellChecker.CheckControlCompleted -= _c1SpellChecker_CheckControlCompleted;
        }
        // monitor spell-checker events
        void _c1SpellChecker_CheckControlCompleted(object sender, CheckControlCompletedEventArgs e)
        {
            if (!e.Cancelled)
            {
                var msg = string.Format("Spell-check complete, {0} errors found.", e.ErrorCount);
                MessageBox.Show(msg, "Spelling");
            }
            WriteLine("CheckControlCompleted: {0} errors found", e.ErrorCount);
            if (e.Cancelled)
            {
                WriteLine("\t(cancelled...)");
            }
        }
        void _c1SpellChecker_BadWordFound(object sender, BadWordEventArgs e)
        {
            WriteLine("BadWordFound: \"{0}\" {1}", e.BadWord.Text, e.BadWord.Duplicate ? "(duplicate)" : string.Empty);
        }              
    }

Spell-Checking

Modal Spell Checking