Question

I am a .Net beginner. I want to color some characters inside a rich text box based on the selected regular expression. How to do this?

Like:

if (Regex.IsMatch(richTextBox, @"^[a-m]{1}$"))
{
   ??? //coloring that particular character of richTextBox
}

What should I write in it? can the same done using label?

Answer 1

You could try using Paragraphs with Runs

Paragraph para = new Paragraph {
    Foreground = Brushes.Red,
};
para.Inlines.Add(new Bold(new Run(matchingString)));
para.Inlines.Add(new Run(regularText));
myRichTextBox.Document.Blocks.Add(para);

etc