Better way to use regex for match and replace

Question

5.00/5 (2 votes)

See more:

Hello

I believe that there is a better way to use RegEx in C# than I have done below:

public override object ProvideValue(IServiceProvider serviceProvider)
{
    Regex r = new Regex("{.+}");
    var matches = r.Matches(String);
    var replacer = new StringBuilder(String);
    foreach (var match in matches)
    {
        var newMatch = match.ToString().Substring(1, match.ToString().Length - 2);
        var value = new StaticResourceExtension(newMatch).ProvideValue(serviceProvider);
        replacer.Replace(match.ToString(), value.ToString());
    }
    return replacer.ToString();
}

What I have tried:

The code above is what I am currently using. But I think there is better..

Posted 1-Mar-18 1:08am

Medtronic WPF Developer

Updated 1-Mar-18 7:09am

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Accepted Answer · 2018-03-01T07:09:00

Solution 2

Something like this should work:

C#

private static readonly Regex Pattern = new Regex("{(.+?)}", RegexOptions.Compiled);

public override object ProvideValue(IServiceProvider serviceProvider)
{
    return Pattern.Replace(String, match =>
    {
        string newMatch = match.Groups[1].Value;
        var value = new StaticResourceExtension(newMatch).ProvideValue(serviceProvider);
        return Convert.ToString(value);
    });
}

Posted 1-Mar-18 7:09am

Richard Deeming

Updated 1-Mar-18 9:41am

v2

Comments

Medtronic WPF Developer 1-Mar-18 14:35pm

Thanks so much I knew there was something, but I completely forgot (it was years ago) and it was hard to find the answer since most information on RegEx is the basic stuff, which is still hard to remember unless you work with it all the time. I figured there was some brain out there I could pick and appreciate that you took the time to answer.

Medtronic WPF Developer 1-Mar-18 15:28pm

You did make a couple of mistakes, but you led me in the right direction. This is the right code in the middle:
return Pattern.Replace(String, match =>
{
var str = match.Groups[0].Value;
var provideStr = str.Substring(1, str.Length - 2);
var value = new StaticResourceExtension(provideStr).ProvideValue(serviceProvider);
return Convert.ToString(value);
});

Richard Deeming 1-Mar-18 15:34pm

No; if you copy the pattern from my answer, match.Groups[1].Value will give you the same thing as your substring code. :)

Grouping Constructs - Regular Expression Language - Quick Reference | Microsoft Docs[^]

Richard Deeming 1-Mar-18 15:40pm

The one problem you might run into is the "greedy" + operator. If you have multiple matches to replace, it will end up processing the whole substring from the first { to the last }.

Change the expression to "{(.+?)}", and you'll get each match individually.

Demo[^]

Maciej Los 1-Mar-18 16:05pm

5ed!

Medtronic WPF Developer 6-Mar-18 19:45pm

Thanks, I fixed it, and works great.

Clifford Nelson 4-Mar-18 12:43pm

Have some things I have not used in this solution. Solid thumbs up.