文件批量改名

private void GhangeNames(string filepath, string sfm, int k)
        {
            DirectoryInfo inf = new DirectoryInfo(filepath);
            FileInfo[] files = inf.GetFiles();
            try
            {
                for (int i = 0; i < files.Length; i++)
                {
                    listBox1.Items.Add(files[i].Name);

&nb