using System;
using System.Text.RegularExpressions;
class Program
{
static void Main(string[] args)
{
string sample = "Space%20Space";
string result = Regex.Replace (
sample,
@"%[0-9a-f][0-9a-f]",
m => ((char) Convert.ToByte (m.Value.Substring (1), 16)).ToString(),
RegexOptions.IgnoreCase
);
Console.WriteLine (result);
}
}
The output:
Space Space