private void WeaponClicked(object sender, ItemClickEventArgs e)
        {
            ListView lv  = (ListView)sender;
            var      isp = (ItemsStackPanel)lv.ItemsPanelRoot;

            _visibleIndex = isp.FirstVisibleIndex;
            WeaponTreeEntry entry = (WeaponTreeEntry)e.ClickedItem;

            Frame.Navigate(typeof(WeaponDetailsPage), entry.Weapon._id);
        }
        public async void LoadData()
        {
            var weapons = await MHDatabaseHelper.GetWeaponsByType(WeaponType);

            WeaponTree = WeaponTreeEntry.GenerateTree(weapons);
        }