public CreateAccountPageViewModel(Frame rootFrame, User user = null)
        {
            _rootFrame = rootFrame;
            IsLoading = false;

            User = user ?? new User();
            User.IdentificationService = "1";
            CreateAccountCommand = new RelayCommand(() => { CreateAccount(); });
        }
        public LoginPageViewModel(Frame rootFrame, User user = null)
        {
            _rootFrame = rootFrame;
            IsLoading = false;

            User = user ?? new User();

            LoginCommand = new RelayCommand(() => { Login(); });
            CreateAccountCommand = new RelayCommand(() => { CreateUSer(); });
        }
        public MainPageViewModel(Frame rootFrame, ObservableCollection<PostDetails> postDetails = null)
        {
            _rootFrame = rootFrame;

            Posts = postDetails ?? new ObservableCollection<PostDetails>();

            LoadPostsCommand = new RelayCommand(() => { LoadPosts(); });

            if (postDetails == null)
                LoadPosts();
        }