编辑 ListBox 项中现有对象的属性 C#

Question

我正在尝试获取搜索到的库存并单击按钮，将其添加到我的订单中的列表框中，以取消下面的代码。 Listbox 项目是一个名为 OrderItems 的对象列表。获取搜索结果后，我检查该项目是否存在于 ListBox 中，只需添加现有项目的 Quantity 属性，否则添加为新项目。逻辑工作正常，它正在循环并识别现有项目，但是 ListBox 中项目的 Quantity 文本不会更改并且始终显示 1。 我正在使用

listBoxItems.DisplayMember = "ItemTitleWithQtyPrice";
listBoxItems.ValueMember = "ItemInventoryId";

还有代码

private void AddItemsToListBox(OrderItem item)
    {            
        Boolean itemExists = false;
        listBoxItems.DisplayMember = "ItemTitleWithQtyPrice";
        listBoxItems.ValueMember = "ItemInventoryId";

        if (listBoxItems != null && listBoxItems.Items.Count > 0)
        {                
            if (listBoxItems.ValueMember != null)
            {                    
                foreach (OrderItem it in listBoxItems.Items)
                {
                    if(it.ItemInventoryId == item.ItemInventoryId)
                    {
                        it.Quantity = it.Quantity + 1;
                        it.CGSTAmount = it.CGSTAmount * it.Quantity;
                        it.SGSTAmount = it.CGSTAmount * it.Quantity;
                        if (it.DiscountAmount > 0)
                        {
                            it.DiscountAmount = it.DiscountAmount * it.Quantity;
                        }
                        it.Total = it.GrossPricePerUnit * it.Quantity;
                        item.ItemTitleWithQtyPrice = item.ItemTitle + " Quantity " + item.Quantity + " Total Price: ₹ " + item.Total;
                        listBoxItems.Update();
                        itemExists = true;

                        GrandTotal = GrandTotal + it.Total;
                        TotalDiscount = TotalDiscount + it.DiscountAmount;
                        TotalTaxAmount = TotalTaxAmount + it.GGSTAmount;

                        order.GrandTotal = GrandTotal;
                        order.TotalDiscount = TotalDiscount;
                        order.TaxAmount = TotalTaxAmount;
                    }       
                }

                if (!itemExists)
                {
                    item.Quantity = 1;
                    item.Total = item.GrossPricePerUnit * item.Quantity;
                    item.DiscountAmount = item.DiscountAmount * item.Quantity;
                    item.GGSTAmount = (item.SGSTAmount + item.CGSTAmount) * item.Quantity;
                    item.ItemTitleWithQtyPrice = item.ItemTitle + " Quantity " + item.Quantity + " Total Price: ₹ " + item.Total;

                    listBoxItems.Items.Add(item);

                    GrandTotal = GrandTotal + item.Total;
                    TotalDiscount = TotalDiscount + item.DiscountAmount;
                    TotalTaxAmount = TotalTaxAmount + item.GGSTAmount;

                    order.GrandTotal = GrandTotal;
                    order.TotalDiscount = TotalDiscount;
                    order.TaxAmount = TotalTaxAmount;
                }
            }
        }
        else
        {
            item.Quantity = 1;
            item.Total = item.GrossPricePerUnit * item.Quantity;
            item.DiscountAmount = item.DiscountAmount * item.Quantity;
            item.GGSTAmount = (item.SGSTAmount + item.CGSTAmount) * item.Quantity;
            item.ItemTitleWithQtyPrice = item.ItemTitle + " Quantity " + item.Quantity + " Total Price: ₹ " + item.Total;

            listBoxItems.Items.Add(item);

            GrandTotal = GrandTotal + item.Total;
            TotalDiscount = TotalDiscount + item.DiscountAmount;
            TotalTaxAmount = TotalTaxAmount + item.GGSTAmount;

            order.GrandTotal = GrandTotal;
            order.TotalDiscount = TotalDiscount;
            order.TaxAmount = TotalTaxAmount;
        }

        txtTotalDiscounts.Text = order.TotalDiscount.ToString();
        txtGrandTotal.Text = order.GrandTotal.ToString();

        //// BIND TO DATA SOURCE DATAGRIDVIEW
        //var bindingList = new BindingList<OrderItem>(items);
        //var source = new BindingSource(bindingList, null);
        //dGridViewOrderedItems.DataSource = source;
    }

Answer 1

您的代码中可能有几个问题，但您提供了更多详细信息。但如果 Quantity 在 listBox 中未显示为更新，请尝试以下代码，在您的意义上为您更新。此代码未经测试检查并给出关于它的反馈。

item.ItemTitleWithQtyPrice = item.ItemTitle + " Quantity " + it.Quantity + " Total Price: ₹ " + item.Total;

还有一件事建议您添加中断；点在您的搜索循环检查中，因为您正在搜索一项或使用 Linq 的概念通过 ID 进行查找。