Question

如何更新购物车数量，我开发了cartview页面，当对所有项目进行更新时，它从文本框中取旧的数量（绑定）而不是我在文本框中写入的新内容。

购物车代码

 public void SetItemQuantity(int productId, int quantity)
        {
            // If we are setting the quantity to 0, remove the item entirely
            if (quantity == 0)
            {
                RemoveItem(productId);
                return;
            }

            // Find the item and update the quantity
            CartItem updatedItem = new CartItem(productId);

            foreach (CartItem item in Items)
            {
                if (item.Equals(updatedItem))
                {
                    item.Quantity = quantity;
                    return;
                }
            }
        }

完整的购物车

<asp:ListView ID="FullCartListView" runat="server" DataKeyNames="ProductID" OnDataBound="FullCartListView_DataBound" OnItemCommand="FullCartListView_ItemCommand">
        <EmptyDataTemplate>
               <table class="table-bordered table table-cart">
        <thead>
          <tr>
       <th>
           No items in shopping cart .
       </th>
          </tr>
           
        </thead>
                                
                           </table>
        </EmptyDataTemplate>
        <ItemTemplate>
            <tbody>
          <tr>
            <td class="cart-product">
              <%--<a href="#" data-toggle="tooltip" title="" class="remove" data-original-title="Remove">&times;</a>--%>
                <asp:LinkButton ID="RemoveLB" data-toggle="tooltip" CssClass="remove" data-original-title="Remove" runat="server" CommandName="Remove" CommandArgument='<%# Eval("ProductID")%>'>
                                    &times;
                                </asp:LinkButton>
              <a href="ProductDetails.aspx?ProductID=<%# Eval("ProductID") %>" title="" class="product-cart">
                <img src="<%=ConfigurationManager.AppSettings["ProductsHTMLPath"].ToString() %><%# Eval("PictureName") %>" width="72" height="100" alt="">
                <h3 class="product-title"><%# Eval("Name") %></h3>
              </a>
            </td>

           <%-- <td>
              <a href="#" data-toggle="tooltip" title="" class="edit-link" data-original-title="Edit">
                <i class="fa fa-edit"></i>
              </a>
            </td>--%>

            <td><span class="amount"><%# Eval("Price") %> </span></td>
            <td><asp:TextBox ID="QuantityTextBox" CssClass="qty" runat="server" Text='<%# Eval("quantity") %>' />
                <asp:Label runat="server" ID="ProductIDLabel" Text='<%# Eval("ProductID") %>' Visible="false" />
                <%-- <br /><br /><asp:Button ID="UpdateCartButton" runat="server" CssClass="btn btn-dark btn-outline" CommandName="Update" CommandArgument="<%# Eval("ProductID") %>" Text="Update"></asp:Button>--%>
            </td>
            <td><span class="amount">
                <asp:Label runat="server" ID="SubTotalPriceLabel" Text='<%# (decimal)Eval("quantity") * (decimal)Eval("Price") %>' />

                </span></td>
          </tr>
        </tbody>
        </ItemTemplate>
        <LayoutTemplate>
            <table id="itemPlaceholderContainer" class="table-bordered table table-cart">
        <thead>
          <tr>
            <th>Product Name</th>
            <%--<th style="width:10%"></th>--%>
            <th style="width:10%">Unit</th>
            <th style="width:10%">QTY</th>
            <th style="width:10%">Subtotal</th>
          </tr>
            <tr id="itemPlaceholder" runat="server">
                        </tr>
        </thead>
                 <tfoot>
          <tr>
            <td colspan="5">
              <div class="text-right">
                <%--<a href="#" role="button" class="btn btn-dark btn-outline">Empty cart</a>--%>
                  <asp:Button ID="EmptyCartButton" runat="server" CssClass="btn btn-dark btn-outline" Text="Empty cart" OnClick="EmptyCartButton_Click"></asp:Button>
                 <asp:Button ID="UpdateCartButton" runat="server" CssClass="btn btn-primary" Text="Update cart" OnClick="UpdateCartButton_Click"></asp:Button>
                <%--<button type="button" class="btn btn-primary">Update cart</button>--%>
              </div>
            </td>
          </tr>
        </tfoot>
                </table>
        </LayoutTemplate>
    </asp:ListView>

更新数量背后的代码

  protected void UpdateCartButton_Click(object sender, EventArgs e)
        {
            for (int i = 0; i < FullCartListView.Items.Count; i++)
            {
                
                TextBox quantity = (TextBox)FullCartListView.Items[i].FindControl("QuantityTextBox");
                Label productid = (Label)FullCartListView.Items[i].FindControl("ProductIDLabel");
                ShoppingCart.ShoppingCart.Instance.SetItemQuantity(Convert.ToInt32(productid.Text), Convert.ToInt32(quantity.Text));

            }

            
            BindData();

        }
                                                             
   protected void BindData()
        {
            FullCartListView.DataSource = ShoppingCart.ShoppingCart.Instance.Items;
            FullCartListView.DataBind();
        }

Answer 1

从你的说法来看，我认为文本框是在回发上绑定的，点击事件发生在回发后，所以如果控件在回发上被数据绑定，文本框中的更新将会丢失

编辑：更具体地说，在调用事件处理程序之前发生回发后的页面加载

Edit2：在您的评论后仔细查看您的代码，您在文本框中使用Eval而不会存储您的更新，请尝试绑定

如何更新购物车数量？

1 个答案: