using System;

using System.IO;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine(MorphPath(@"C:\test\perf.log", 1));

        Console.WriteLine(MorphPath(@"C:\test\perf.log", 2));

        Console.WriteLine(MorphPath(@"C:\test\perf.log", 3));

        Console.WriteLine(MorphPath(@"C:\test\perf.log", 4));

    }

            private static string MorphPath(string path, int retry)

        {

            string dir = Path.GetDirectoryName(path);

            string fileName = Path.GetFileNameWithoutExtension(path);

            string ext = Path.GetExtension(path);

​

            return Path.Combine(dir, string.Format("{0}-{1}{2}", fileName, retry, ext));

        }

}