VirtualFileSystem.VFS.GetPathName C# (CSharp) Method

        public static String GetPathName(String path)
        {
            AssertPathValid(path);
            var pos = path.LastIndexOf('/');
            return path.Substring(pos + 1);
        }

            public File(VFSCore vfs, String path, FileMode fileMode)
            {
                this.vfs = vfs;

                var directory = VFS.GetPathDirectory(path);
                var name      = VFS.GetPathName(path);

                VFS.AssertNameValid(name);

                INodeDirectory dir = INodeDirectory.Resolve(vfs, directory);

                if (dir == null)
                {
                    throw new Exception("无法访问目录");
                }
                switch (fileMode)
                {
                case FileMode.CreateNew:
                    if (dir.Contains(name))
                    {
                        throw new Exception("文件已存在");
                    }
                    CreateFile(dir, name);
                    break;

                case FileMode.Create:
                    if (dir.Contains(name))
                    {
                        OpenFile(dir, name);
                        inode.Resize(0);
                    }
                    else
                    {
                        CreateFile(dir, name);
                    }
                    break;

                case FileMode.Open:
                    if (!dir.Contains(name))
                    {
                        throw new Exception("文件未找到");
                    }
                    OpenFile(dir, name);
                    break;

                case FileMode.OpenOrCreate:
                    if (dir.Contains(name))
                    {
                        OpenFile(dir, name);
                    }
                    else
                    {
                        CreateFile(dir, name);
                    }
                    break;

                case FileMode.Truncate:
                    if (!dir.Contains(name))
                    {
                        throw new Exception("文件未找到");
                    }
                    OpenFile(dir, name);
                    inode.Resize(0);
                    break;

                case FileMode.Append:
                    if (!dir.Contains(name))
                    {
                        CreateFile(dir, name);
                    }
                    else
                    {
                        OpenFile(dir, name);
                        position = inode.data.sizeByte;
                    }
                    break;

                default:
                    throw new ArgumentException();
                }
            }