AutoCorrect

  • 5 minutes to read

The DXRichEdit AutoCorrect feature can help you automate inserting frequently used text, auto-correcting typing errors and misspelled capitalization. You can specify the built-in options, construct a custom replacement table or handle the Autocorrect event to analyze the input text and provide the necessary substitution.

Built-in Automatic Correction Options

The following members enable you to enable certain automatic correction features:

Property Description
DXRichEditAutoCorrectOptions.DetectUrls Automatically detects an inserted web address, a network path or email address and converts it to a hyperlink.
DXRichEditAutoCorrectOptions.CorrectTwoInitialCapitals Corrects capitalization errors.
DXRichEditAutoCorrectOptions.ReplaceTextAsYouType Scans for entries as you type and replaces them with the designated text or image.
DXRichEditAutoCorrectOptions.UseSpellCheckerSuggestions Automatically detects and corrects typos and misspelled word if the RichEditControl.SpellChecker property specifies a spell checker component. If the spell checker provides one suggestion, this suggestion automatically substitutes the incorrect word. Otherwise, no changes are made.

Access the built-in autocorrect options in XAML as shown in the code snippet below:

<dxre:RichEditControl x:Name="richEditControl1" DocumentSource="{Binding DataBaseDocumentSource}" CommandBarStyle="Ribbon">
     <dxre:RichEditControl.AutoCorrectOptions>
         <dxre:DXRichEditAutoCorrectOptions DetectUrls="False" UseSpellCheckerSuggestions="True" CorrectTwoInitialCapitals="True" />
     </dxre:RichEditControl.AutoCorrectOptions>
</dxre:RichEditControl>

Automatic Correction Using Table Entries

The text expander functionality allows you to insert symbols, decipher abbreviations and insert images. Follow the steps below to implement the text expander:

  1. Create a new AutoCorrectReplaceInfoCollection instance and fill it with AutoCorrectReplaceInfo entries:

    private AutoCorrectReplaceInfoCollection LoadAbbrevs(string path)
    {
       AutoCorrectReplaceInfoCollection coll = new AutoCorrectReplaceInfoCollection();
       string aLine = "";
    
       AutoCorrectReplaceInfo acrInfoIm = new AutoCorrectReplaceInfo(":-)", CreateImageFromResx("smile.png"));
       coll.Add(acrInfoIm);
    
       if (File.Exists(path))
       {
         StreamReader sr = new StreamReader(path);
         while (!(sr.EndOfStream))
           {
             aLine = sr.ReadLine();
             if (aLine != "START") continue;
    
             while (!(sr.EndOfStream))
              {
                aLine = sr.ReadLine();
                aLine = aLine.Trim();
                string[] words = aLine.Split('=');
                if (words.Length == 2)
                 {
                   AutoCorrectReplaceInfo acrInfo = new AutoCorrectReplaceInfo(words[0], words[1]);
                   coll.Add(acrInfo);
                 }
              }
          }
            sr.Close();
       }
         return coll;
    }
    
  2. Call the IAutoCorrectService.SetReplaceTable method to register a created replacement list. Register the service after the RichEditControl instance is completely loaded, i.e. in the Window.Loaded event handler.

    private void ThemedWindow_Loaded(object sender, RoutedEventArgs e)
     {
        IAutoCorrectService svc = richEditControl1.GetService<IAutoCorrectService>();
        if (svc != null)
            svc.SetReplaceTable(LoadAbbrevs("abbvs.txt"));
     }
    
  3. When you type a space, punctuation mark or carriage return (a character that typically means you have finished typing a word), AutoCorrect compares the word (or more precisely the group of characters) against its list of entries. If the word matches an entry, AutoCorrect substitutes this word with a replacement object.

    In this example, the substitution is performed as shown in the animation below:

    DXRichEdit_AutoCorrect_Substitution

Automatic Correction Using the AutoCorrect Event

Handle the RichEditControl.AutoCorrect event to analyze the input text and provide a specific object for replacement. Use the following API (accessible using the AutoCorrectEventArgs.AutoCorrectInfo property) to perform the desired actions:

API Description
AutoCorrectInfo.Text Gets the input string to check whether it should be replaced.
AutoCorrectInfo.IncrementStartPosition Decreases a text range being analyzed by moving its start by one position.
AutoCorrectInfo.DecrementStartPosition Extends a text range being analyzed by moving its start by one position.
AutoCorrectInfo.IncrementEndPosition Extends a text range being analyzed by moving its end by one position.
AutoCorrectInfo.DecrementEndPosition Decreases a text range being analyzed by moving its end by one position.
AutoCorrectInfo.ReplaceWith Gets or sets the object used to replace the input string in the document.

The RichEditControl.AutoCorrect event is handled to replace the typed $ symbol with a picture of a dollar, and substitute the text enclosed in percent symbols with custom content.

To accomplish this task, a document text obtained via the AutoCorrectEventArgs.AutoCorrectInfo property is amended by expanding its left boundary using the AutoCorrectInfo.DecrementStartPosition method, until a special symbol or a word separator symbol is found. If a resulting string meets certain conditions, such as whether it is a dollar sign or a %date% string, a replacement object is passed to the document via the AutoCorrectInfo.ReplaceWith property. A replacement object can be a string or an image.

Private Sub richEditControl1_AutoCorrect(ByVal sender As Object, ByVal e As DevExpress.XtraRichEdit.AutoCorrectEventArgs)
    Dim info As AutoCorrectInfo = e.AutoCorrectInfo
    e.AutoCorrectInfo = Nothing

    If info.Text.Length <= 0 Then
        Return
    End If
    Do
        If Not info.DecrementStartPosition() Then
            Return
        End If

        If IsSeparator(info.Text(0)) Then
            Return
        End If

        If info.Text(0) = "$"c Then
            info.ReplaceWith = CreateImageFromResx("dollar_pic.png")
            e.AutoCorrectInfo = info
            Return
        End If

        If info.Text(0) = "%"c Then
            Dim replaceString As String = CalculateFunction(info.Text)
            If Not String.IsNullOrEmpty(replaceString) Then
                info.ReplaceWith = replaceString
                e.AutoCorrectInfo = info
            End If
            Return
        End If
    Loop
End Sub