void listItemSelected(object sender, SelectedItemChangedEventArgs e)
        {
            var todoItem = (TodoItem)e.SelectedItem;
            var todoPage = new RegisterForm();

            todoPage.BindingContext = todoItem;

            Navigation.PushAsync(todoPage);
        }
        public HomePage()
        {
            InitializeComponent();

            ToolbarItem tbi = null;

            if (Device.OS == TargetPlatform.iOS)
            {
                tbi = new ToolbarItem("+", null, () =>
                {
                    var todoItem            = new TodoItem();
                    var todoPage            = new RegisterForm();
                    todoPage.BindingContext = todoItem;
                    Navigation.PushAsync(todoPage);
                }, 0, 0);
            }
            if (Device.OS == TargetPlatform.Android)
            {
                tbi = new ToolbarItem("New Donor", "plus", () =>
                {
                    var todoItem            = new TodoItem();
                    var todoPage            = new RegisterForm();
                    todoPage.BindingContext = todoItem;
                    Navigation.PushAsync(todoPage);
                }, 0, 0);
            }


            ToolbarItems.Add(tbi);

            if (Device.OS == TargetPlatform.iOS)
            {
                var tbi2 = new ToolbarItem("?", null, () =>
                {
                    var todos   = App.Database.GetItems();
                    var tospeak = "";
                    foreach (var t in todos)
                    {
                        tospeak += t.Name + " ";
                    }
                }, 0, 0);
                ToolbarItems.Add(tbi2);
            }

            DonorView.ItemsSource = App.Database.GetItems();
            sbSearch.TextChanged += (sender2, e2) => FilterBloodType(sbSearch.Text);
        }