Question

尝试在Xamarin.Android中开发物品订购系统。为了显示项目列表，我在每行中都使用了带有自定义适配器的listView和Cart按钮。你能否告诉我应该使用哪种技术，或者如何将每个订购的商品存储在我的购物车列表活动列表中？这是我的itemListAdapter类：

谢谢！

My ItemList Image

namespace Test.Restaurant.Android.Adapters
{
public class ItemListAdapter : BaseAdapter
{
List mItems;
Activity context;
private OrderDetail _OrderDetails;
private List _OrderDetailsList;

    public ItemListAdapter(Activity context, List<Item> items) : base()
    {
        this.context = context;
        this.mItems = items;
    }

    public override long GetItemId(int position)
    {
        return position;
    }

    public override Item this[int position]
    {
        get { return mItems[position]; }
    }

    public override int Count
    {
        get { return mItems.Count; }
    }

    public override View GetView(int position, View convertView, ViewGroup parent)
    {

        View view = convertView ?? context.LayoutInflater.Inflate(Resource.Layout.ItemRowView, parent, false);
        var viewHolder = view.Tag as ItemHolder;
        var item = mItems[position];
        Bitmap myImage = ImageHelper.Bytes2Bimap(item.Image);

        // 03. List With Custom Row View           

        if (viewHolder == null)
        {

            viewHolder = new ItemHolder
            {
                itemNameTextView = view.FindViewById<TextView>(Resource.Id.itemNameTextView),
                descriptionTextView = view.FindViewById<TextView>(Resource.Id.descriptionTextView),
                itemImageView = view.FindViewById<ImageView>(Resource.Id.itemImageView),
                priceTextView = view.FindViewById<TextView>(Resource.Id.priceTextView),                    
                btnPlus = view.FindViewById<ImageView>(Resource.Id.btnPlus),
                btnMinus = view.FindViewById<ImageView>(Resource.Id.btnMinus),
                btnAddtoCart = view.FindViewById<ImageView>(Resource.Id.btnAddToCart),
                txtQty = view.FindViewById<TextView>(Resource.Id.cart_product_quantity)
            };
            view.Tag = viewHolder;
        }
        else
        {
            viewHolder = view.Tag as ItemHolder;
        }


        viewHolder.itemNameTextView.Text = item.ItemName;
        viewHolder.descriptionTextView.Text = item.ItemDescription;
        viewHolder.priceTextView.Text = "$ " + 30;
        viewHolder.itemImageView.SetImageBitmap(myImage); 


        if (!viewHolder.btnAddtoCart.HasOnClickListeners)
        {

            viewHolder.btnAddtoCart.Click += (sender, args) =>
            {

                _OrderDetails = new OrderDetail();
                _OrderDetails.ItemId = item.ItemId;
                _OrderDetails.Quantity = int.Parse(viewHolder.txtQty.Text);
                _OrderDetails.UnitPriceInclTax = 0;
                _OrderDetails.UnitPriceExclTax = 0;
                _OrderDetails.DiscountAmountInclTax = 0;
                _OrderDetails.DiscountAmountExclTax = 0;
                _OrderDetails.PriceInclTax = 100;
                _OrderDetails.PriceExclTax = 0;


             **   //What should I Do Here???**

        **************************
        **************************
            };
        }

        return view;

    }


    private class ItemHolder : Java.Lang.Object
    {
        public TextView itemNameTextView { get; set; }
        public TextView descriptionTextView { get; set; }
        public TextView txtQty { get; set; }
        public ImageView itemImageView { get; set; }
        public ImageView btnPlus { get; set; }
        public ImageView btnMinus { get; set; }
        public ImageView btnAddtoCart { get; set; }
    }
}
}

Answer 1

您能告诉我应该使用哪种技术，或者如何将列出的所有订购商品存储到我的购物车列表活动中？

您需要将CartLilst（List<OrderDetail>）传递给适配器：

public class ItemListAdapter : BaseAdapter
{
   ...
   List<OrderDetail> cartList;

   public ItemListAdapter(Activity context, List<Item> items, List<OrderDetail> cartList)
    {
        this.context = context;
        this.mItems = items;
        _cartlist = cartList;
    }
  ...
}

当用户点击addToCart按钮时，将OrderDetail添加到此列表中：

viewHolder.btnAddtoCart.Click += (sender, args) =>
{

     _OrderDetails = new OrderDetail();
     _OrderDetails.ItemId = item.ItemId;
     _OrderDetails.Quantity = int.Parse(viewHolder.txtQty.Text);
     _OrderDetails.UnitPriceInclTax = 0;
     _OrderDetails.UnitPriceExclTax = 0;
     _OrderDetails.DiscountAmountInclTax = 0;
     _OrderDetails.DiscountAmountExclTax = 0;
     _OrderDetails.PriceInclTax = 100;
     _OrderDetails.PriceExclTax = 0;


     //add _OrderDetail to cartList
     cartList.Add(_OrderDetails);
};

应该在适配器创建之前的Activity中初始化并创建列表：

List<OrderDetail> cartList=new List<OrderDetail>();
ItemListAdapter adapter=new ItemListAdapter(this,items,cartList);

<强>更新

如果您的购物车清单在您的应用程序中经常使用，那么我建议您忘记我所说的内容，并使用单一模式将购物车列表存储在您的应用中：

在您的应用中创建CartList.cs：

public class CartList
{
    private static List<OrderDetail> _cartList;
    public static List<OrderDetail> Instance
    {
        get
        {
            if (_cartList == null)
            {
                _cartList = new List<OrderDetail>();
            }
            return _cartList;
        }
        set
        {
            _cartList = value;
        }
    }
}

然后你可以在你的应用程序的任何地方使用这个CartList（你不需要将它传递给你的新Activity，你可以直接在你的新Activity中获取它）：
```
var cartList=CartList.Instance;
```

如何将每个订购的商品存储在Xamarin.Android的购物车清单中？

1 个答案: