C# - String Extensions - AddMarkup

Usage

string foo = "I got this from Just Snippets!";
string bar = foo.AddMarkup("Just Snippets", "", "");

would set bar to "I got this from Just Snippets!".

Snippet

namespace My.Helpers
{
    // String extension methods.

    public static class StringExtensions
    {
        public static string AddMarkup(this string text, string value, string before, string after, bool ignoreCase = true)
        {
            string work = text;
            int start = 0;
            System.StringComparison caseSensitivity;
            int bump = value.Length + before.Length + after.Length;

            if (ignoreCase)
                caseSensitivity = System.StringComparison.CurrentCultureIgnoreCase;
            else
                caseSensitivity = System.StringComparison.CurrentCulture;

            while (true)
            {
                int i = work.IndexOf(value, start, caseSensitivity);
                if (i < 0) break;

                work = work.Left(i) + before + work.Substring(i, value.Length) + after
                    + work.Right(work.Length - i - value.Length);

                start += bump;
            }

            return work;
        }