递归获取XML元素

看到的一道题，用递归获取XML元素....

        static void Main(string[] args)

        {

            string xmlContent = @"<FileSystem>

                                    <DriverC>

                                      <Dir DirName='MSDOS622'>

                                        <File FileName ='Command.com' ></File>

                                      </Dir>

                                      <File FileName ='MSDOS.SYS' ></File>

                                      <File FileName ='IO.SYS' ></File>

                                    </DriverC>

                                    <DriverC>

                                      <Dir>

                                        <File FileName ='DriverC.com' ></File>

                                      </Dir>

                                      <File FileName ='DriverC.SYS' ></File>

                                      <File FileName ='DriverCIO.SYS' ></File>

                                    </DriverC>

                                  </FileSystem>";

            var parentElement = XElement.Parse(xmlContent);

            var elements = FindElements(parentElement.Elements(), "File");

        }

        public static IList<XElement> FindElements(IEnumerable<XElement> elements, string elementName)

        {

            if(elements==null||elements.Count()==

                ||string.IsNullOrWhiteSpace(elementName))

            {

                return new List<XElement>();

            }

            var selectedElements = new List<XElement>();

            foreach (var element in elements)

            {

                if (element.HasElements)

                {

                    selectedElements.AddRange(FindElements(element.Elements(), elementName));

                }

                else

                {

                    if (string.Equals(element.Name.LocalName, elementName))

                    {

                        selectedElements.Add(element);

                    }

                }

            }

            return selectedElements;

        }