Find text in RTB is very slow ?[Resolved]

This method works but it's damn slow . It takes about 1 minute to colorize some keywords . I feel like there is a way to improve it and speed it up . Anyone has a solution or alternative method ?

VB Code:

Public Sub FindHighlight(ByVal Keywords As ArrayList, ByVal HighlightColor As Color)
        Me.SuspendLayout()
        Dim StartLooking As Integer = 0
        Dim FoundAt As Integer
        Dim SearchLength As Integer        
 
        For Each keyword As String In Keywords
 
            SearchLength = keyword.Length
            Application.DoEvents()
            Do
                FoundAt = Me.RichTextBox1.Find(keyword, StartLooking, RichTextBoxFinds.WholeWord)
                If FoundAt > -1 Then Me.RichTextBox1.SelectionColor = HighlightColor
                StartLooking = StartLooking + SearchLength
            Loop While FoundAt > -1
            SearchLength = 0
            FoundAt = 0
            StartLooking = 0
        Next
 
        Me.ResumeLayout()
    End Sub

btw , I'll not go with threading now .It's my last option , I think :sick:


Thanks

use Regex Pirate mate :)
it's great on Keywords , you can use the Index and Length properties on the Match to select / highlight / carry on to the next found item. it's about the fastest i've found for highlighting in RTF.

Any example , demo .. I've never tried regex before :(

a very simple example ( cuz it's sunday and we been having a family day ) ...

VB Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim keywords() As String = {"public", "private", "void", "class", "string"}
        For Each keyword As String In keywords
            Dim rgx As New Regex(keyword & "\s*([^a-z,0-9]+)", RegexOptions.IgnoreCase)
            Dim mCol As MatchCollection = rgx.Matches(rtfSyntax.Text)
            For Each m As Match In mCol
                rtfSyntax.Select(m.Index, m.Length)
                rtfSyntax.SelectionColor = Color.Blue
            Next
        Next
    End Sub

God bless you and your family . :)

I got the idea and I can go on with my project .;)

Great example. You should work up a small sample project and put it in the .Net Code Bank.

sysop :D , small glitch in the pattern applied !!

It extends the color to some chars like (# , () in tostring() function ) . It doesn't seem to be %100 accurate . And also , how can I make it differenciate between string and tostring (it colorize both).:ehh:

like i said , a basic example. you need to specify if you want spaces before / after a string with regex
\s+private\s+ would search for the word " private " with a space before and after it , but it will prevent you from finding all cases of the word ( eg: if you are at the begining or end of a row of text )
to search for the word but not allow chars before or after ( eg: privateW fails , wPrivate fails , private succeeds ) ...

PHP Code:

---

"\s*([^a-z,0-9]+)" & keyword & "\s*([^a-z,0-9]+)" 


---

Using keyword as a pattern works . Thanks for explanation though . :)

PHP Code:

---

"\s" + keyword + "\s" 


---

This works better , but I'm having trouble with comment lines . I don't want to highlight keywords in comments . How can I skip like this " # region " or " // private fields ...etc" ??