Highlighting Language Syntax

Hey does anyone know of a effiecient method of highlighting a richtext box for keywords. When I open the file and format the colors this is the code that i use for the keywords

Code:

---

foreach(string word in this.ReservedWords)
 {                 
          Regex rgx=new Regex(word , RegexOptions.IgnoreCase);
          MatchCollection mCol=rgx.Matches(this.rtfSource.Text);
          foreach(Match m in mCol)
          {
                        this.rtfSource.HideSelection=true;
                        this.rtfSource.Select(m.Index , m.Length);
                        this.rtfSource.SelectionColor=Color.Blue;
                        this.rtfSource.SelectionStart=m.Index + m.Length;
                        this.rtfSource.SelectionLength=0;
          }
 }

---

This takes a long time to format, does anyone have any sugestions of a better way?

Thanks

I had a go at it recntly in VB and C#. After trying a while with different algorithms i came to the conclusion that no matter how fast is your algoritm it wont be able to cope if you have large amount of text. So I did some searching and found that the best approach is to color only visble lines not "ALL" lines. If you notice MS FrontPage ueses the same technique. Here is a very good example in VB.Net(can convert it to C#), there are more on CodePrject. Hope it helps.

http://www.codeproject.com/vb/net/re...axcoloring.asp

Cheers Working Perfectly :)

Thanks