System.IO.DirectoryInfo.GetFileSystemInfos C# (CSharp) Method

        public System.IO.FileSystemInfo[] GetFileSystemInfos(string searchPattern, System.IO.SearchOption searchOption) { throw null; }
        public void MoveTo(string destDirName) { }

 public IEnumerable<string> FileAndFolderNamesIn(string path, string searchPattern = null)
 {
     var directoryInfo = new DirectoryInfo(path);
     if (string.IsNullOrEmpty(searchPattern))
     {
         return directoryInfo.GetFileSystemInfos().Select(info => info.Name).ToList();
     }
     return directoryInfo.GetFileSystemInfos(searchPattern).Select(info => info.Name).ToList();
 }