public PressureItemDetailPage()
        {
            InitializeComponent();

            var pressureItem = new PressureItem
            {
                Date              = DateTime.MinValue,
                SystolicPressure  = 0,
                DiastolicPressure = 0,
                Pulse             = 0
            };

            viewModel      = new PressureItemDetailViewModel(pressureItem);
            BindingContext = viewModel;
        }
        public PressureItemDetailPage(PressureItemDetailViewModel viewModel)
        {
            InitializeComponent();

            BindingContext = this.viewModel = viewModel;
        }