Lesson 1 - Add Spell Checking to Your Application

• Sep 27, 2023
• 3 minutes to read

This topic will show how to add spell-check functionality to your application, using the SpellChecker component. Dictionaries for US English are built-in and will be used by default.

Note

If no dictionary is specified, SpellChecker uses default English dictionary. When any other dictionary is added, even a custom dictionary, default dictionary is not loaded. Note that the default English dictionary is used when the machine’s current culture is EN-US.

The SpellChecker component can check the spelling of a wide range of text editors.

Please follow the steps below. We assume that your application’s form has several different text editors from the list of supported controls.

Step 1. Add a SpellChecker Component

Add the SpellChecker component to your project. To do this, simply drag the corresponding item from the DX.23.2: Components toolbox tab, and drop it onto the form that contains text controls.

Step 2. Add Code for Check Spelling On Demand

To start checking the spelling in all supported controls on the form when clicking the button:

• Add the SimpleButton control (located on the DX.23.2: Common Controls toolbox tab) to the form;
• Subscribe to the button’s Click event.

• To start spell checking and invoke the spelling dialog to make corrections when you click the button, call the SpellChecker.CheckContainer method.

  Form1.cs

  private void simpleButton1_Click(object sender, EventArgs e) {
      spellChecker1.CheckContainer(this);
  }
  

  Form1.vb

  Private Sub simpleButton1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles simpleButton1.Click
      spellChecker1.CheckContainer(Me)
  End Sub
  

Step 3. Add Code for Check Spelling As You Type

To enable SpellChecker to check the spelling of all supported controls on the form as you type:

• Subscribe to the form’s Load event;

• Add the following code to the Load event handler:

  View Example

  Form1.cs

  private void Form1_Load(object sender, EventArgs e)
  {
      // Set spell checking options.
      spellChecker1.SpellCheckMode = DevExpress.XtraSpellChecker.SpellCheckMode.AsYouType;
      spellChecker1.ParentContainer = this;
      spellChecker1.CheckAsYouTypeOptions.CheckControlsInParentContainer = true;
      // Set focus to the RichTextBox control to show red wavy lines under misspelled words.
      richTextBox1.Select();
  }
  

  Form1.vb

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
      ' Set spell checking options.
      spellChecker1.SpellCheckMode = DevExpress.XtraSpellChecker.SpellCheckMode.AsYouType
      spellChecker1.ParentContainer = Me
      spellChecker1.CheckAsYouTypeOptions.CheckControlsInParentContainer = True
      ' Set focus to the RichTextBox control to show red wavy lines under misspelled words.
      richTextBox1.Select()
  End Sub
  

  This code instructs the SpellChecker to underline the misspelled word when the end-user finishes typing the word or moves the cursor after changing it. The user can then right-click a word and select a suggestion from the context menu.

Note

SpellChecker relies on an application message loop - selection and tracking text changes are performed on Application.Idle event. If the event isn’t raised, you may experience issues with SpellChecker (for example, underlines are not be updated). Raise the Idle event manually to overcome this behavior. An optimal solution is to call the `Application.RaiseIdle`` method on a timer.

Step 4. Run the project

The misspelled words are underlines in the text control which has the focus. The RichEditControl always display underlines whether it has focus or not, as illustrated in the following picture:

Click the Check Spelling button to start spelling check for all controls on the form and invoke the Spelling Dialog.