How to: Use WPF Spell Checker in MVVM Applications
- 4 minutes to read
This topic explains how to use the MVVM approach to manage Spell Checker integrated into a text-aware control. This approach allows you to handle spell-checker events or store dictionary files in a database.
If your application does not require tracking user interaction or UI customization, you can add a spell checking behavior and manage it in XAML. Refer to the following article for more information: Configure Spell-Checking Behavior.
Create and Bind a Spell Checker
You can use the SpellingSettings option to integrate the Spell Checker into a supported text-aware control.
In the ViewModel class, create a SpellChecker class instance and specify its Culture, SpellingFormType, and SpellCheckMode properties.
using DevExpress.Mvvm;
using DevExpress.Xpf.SpellChecker;
using DevExpress.XtraSpellChecker;
// ...
public class MainViewModel
{
// ...
public virtual SpellChecker SpellChecker { get; set; }
// ...
{
// Create a SpellChecker class instance.
SpellChecker = new SpellChecker();
// Specify the SpellChecker's properties.
SpellChecker.SpellingFormType = SpellingFormType.Word;
SpellChecker.SpellCheckMode = SpellCheckMode.AsYouType;
SpellChecker.Culture = new CultureInfo("de-DE");
// ...
}
In XAML, add references to the following namespaces:
xmlns:ViewModel="clr-namespace:DXSpellCheckerBindingDictionaries.ViewModel"
xmlns:dxsch="http://schemas.devexpress.com/winfx/2008/xaml/spellchecker"
Bind the attached SpellingSettings.SpellChecker property to the created SpellChecker object to enable spell check for a text editor. You can bind this property at the level of the root container to enable this functionality for its children.
<Grid dxsch:SpellingSettings.SpellChecker="{Binding SpellChecker}"
dxsch:SpellingSettings.CheckAsYouType="True"
dxsch:SpellingSettings.ShowSpellCheckMenu="True"
dxsch:SpellingSettings.UnderlineColor="Blue"
dxsch:SpellingSettings.UnderlineStyle="WavyLine"
dxsch:SpellingSettings.DictionarySourceCollection="{Binding Dictionaries, UpdateSourceTrigger=PropertyChanged}">
Bind Dictionaries
Create a DictionarySourceCollection Dictionaries property to bind dictionaries. Create a new DictionarySourceCollection and add a new dictionaries to it. Specify the dictionary file, the affix file, and the culture settings of the dictionary.
public class MainViewModel
{
public virtual DictionarySourceCollection Dictionaries { get; set; }
// ...
public MainViewModel()
{
// ...
Dictionaries = GetDictionaries();
// ...
}
// ...
public DictionarySourceCollection GetDictionaries()
{
// Create a dictionary collection.
var collection = new DictionarySourceCollection();
// Create a Hunspell spell-checking dictionary.
var dictionary = new HunspellDictionarySource() { Culture = new CultureInfo("de-DE") };
// Load the dictionary file.
dictionary.DictionaryUri = new Uri(@"pack://application:,,,/DXSpellCheckerBindingDictionaries;component/Dictionaries/de_DE.dic");
// Load the affix file.
dictionary.GrammarUri = new Uri(@"pack://application:,,,/DXSpellCheckerBindingDictionaries;component/Dictionaries/de_DE.aff");
// Add the dictionary to the collection.
collection.Add(dictionary);
var customDictionary = new SpellCheckerCustomDictionarySource() { Culture = new CultureInfo("EN-us") };
customDictionary.DictionaryUri = new Uri(@"pack://application:,,,/DXSpellCheckerBindingDictionaries;component/Dictionaries/CustomEnglish.dic");
customDictionary.AlphabetUri = new Uri(@"pack://application:,,,/DXSpellCheckerBindingDictionaries;component/Dictionaries/Alphabet.txt");
collection.Add(customDictionary);
return collection;
}
In XAML, bind the SpellingSettings.DictionarySourceCollection to the Dictionaries property:
<Grid dxsch:SpellingSettings.SpellChecker="{Binding SpellChecker}"
dxsch:SpellingSettings.CheckAsYouType="True"
dxsch:SpellingSettings.ShowSpellCheckMenu="True"
dxsch:SpellingSettings.UnderlineColor="Blue"
dxsch:SpellingSettings.UnderlineStyle="WavyLine"
dxsch:SpellingSettings.DictionarySourceCollection="{Binding Dictionaries, UpdateSourceTrigger=PropertyChanged}">
Handle Spell Checker Events
Subscribe to and handle spell checker events in the ViewModel class. Refer to the following table for a complete list of available events: SpellChecker Events
The following code snippet handles the SpellingFormShowing and RepeatedWordFound events:
{
// ...
// Subscribe to events
SpellChecker.RepeatedWordFound += SpellChecker_RepeatedWordFound;
SpellChecker.CheckCompleteFormShowing += SpellChecker_CheckCompleteFormShowing;
}
private void SpellChecker_CheckCompleteFormShowing(object sender, FormShowingEventArgs e)
{
MessageBoxService.Show("That's It!");
e.Handled = true;
}
private void SpellChecker_RepeatedWordFound(object sender, RepeatedWordFoundEventArgs e)
{
e.Result = SpellCheckOperation.Cancel;
}
This example uses the DXMessageBoxService to show a message. Register this service in XAML:
<dxmvvm:Interaction.Behaviors>
<dx:DXMessageBoxService />
</dxmvvm:Interaction.Behaviors>