C++ 如何检测一个目录下的文件被占用

    public bool IsFileLocked(string filename)
        {
            bool Locked = false;
            try
            {
                FileStream fs =
                    File.Open(filename, FileMode. OpenOrCreate,
                    FileAccess.ReadWrite, FileShare.None);
                fs.Close();
            }
            catch (IOException ex)
            {
                Locked = true;
            }
            return Locked;
        }