Re: Converting a string

Lovely solution Mike.  Would you mind if I blogged it, with full credit of
course?

> -----Original Message-----
> From: Discussion forum for developers using Windows Forms to build apps
> and controls [mailto:[email protected]] On Behalf Of
> Mike Woodring
> Sent: 06 September 2007 06:17 PM
> To: [email protected]
> Subject: Re: [DOTNET-WINFORMS] Converting a string
>
> > We can do the following
> >
> > X = ScaleCommand.Replace("Chr(27)", chr(27))
> > X = X.Replace("Chr(13)",chr(13)
> >
> > And so forth for each unprintable.
> >
> > The result will be what is needed.
> >
> > I am now going to look at patterns for a simpler solution.
>
> If you stick with putting "Chr(##)" in the DB, then one approach to a
> more
> general purpose replacement solution is to use the variation of
> Regex.Replace that takes a MatchEvaluator (delegate).  Then you can
> encode
> any arbitrary chr(#) pattern in the data, and the code can simply
> convert
> all such patterns into their corresponding character codes.
>
> This is in C#, not VB, but it should give you the basic idea:
>
> string newString =
>   Regex.Replace( inputText,
>                  @"(chr\((?<code>\d+)\))",
>                  delegate(Match m)
>                  {
>                    return
> Convert.ToChar(Convert.ToInt32(m.Result("${code}"))).ToString();
>                  },
>                  RegexOptions.IgnoreCase );
>
> The regex pattern matches any occurrence of chr(#) [where # can be 1 or
> more
> occurrences of 0-9].  For each such match, the delegate supplied will
> be
> invoked.  That delegate (shown above as an anonymous method) converts
> the
> string form of the match (eg: "27") into the corresponding integer
> value,
> then into the corresponding character value, then back into a string
> representation (which is what the match evaluator method must return).
>
> Or, since it sounds like you're going to be using the regex repeatedly
> over
> the course of your program, you should instead setup the regex once
> ahead of
> time:
>
> Regex regex = new Regex(@"(chr\((?<code>\d+)\))",
> RegexOptions.IgnoreCase);
>
> And then just use that regex instance repeatedly to do the
> search/replace
> operation:
>
> string newString =
>   regex.Replace( inputText,
>                  delegate(Match m)
>                  {
>                    return
> Convert.ToChar(Convert.ToInt32(m.Result("${code}"))).ToString();
>                  } );
>
> -Mike
> Bear Canyon Consulting LLC
> http://www.bearcanyon.com
> http://www.pluralsight.com/mike