FastColoredTextBoxNS.SyntaxHighlighter.VBAutoIndentNeeded C# (CSharp) Method

        private void VBAutoIndentNeeded(object sender, AutoIndentEventArgs args)
        {
            //end of block
            if (Regex.IsMatch(args.LineText, @"^\s*(End|EndIf|Next|Loop)\b", RegexOptions.IgnoreCase))
            {
                args.Shift = -args.TabLength;
                args.ShiftNextLines = -args.TabLength;
                return;
            }
            //start of declaration
            if (Regex.IsMatch(args.LineText,
                @"\b(Class|Property|Enum|Structure|Sub|Function|Namespace|Interface|Get)\b|(Set\s*\()",
                RegexOptions.IgnoreCase))
            {
                args.ShiftNextLines = args.TabLength;
                return;
            }
            // then ...
            if (Regex.IsMatch(args.LineText, @"\b(Then)\s*\S+", RegexOptions.IgnoreCase))
                return;
            //start of operator block
            if (Regex.IsMatch(args.LineText, @"^\s*(If|While|For|Do|Try|With|Using|Select)\b", RegexOptions.IgnoreCase))
            {
                args.ShiftNextLines = args.TabLength;
                return;
            }

            //Statements else, elseif, case etc
            if (Regex.IsMatch(args.LineText, @"^\s*(Else|ElseIf|Case|Catch|Finally)\b", RegexOptions.IgnoreCase))
            {
                args.Shift = -args.TabLength;
                return;
            }

            //Char _
            if (args.PrevLineText.TrimEnd().EndsWith("_"))
            {
                args.Shift = args.TabLength;
            }
        }