Find text in RTB is very slow ?[Resolved]

[Pirate]

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 ?

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


Thanks