Question

我有一个WinForm C＃应用程序，允许服务员从餐馆接受客户订单。目前，从下图中可以看到输出menu.xml文件的datagridview。一旦服务员选择了一餐和一个座位，该信息就会传递到一个名为order.xml的新xml文件中。我已经完成了所有这些工作。

我需要帮助的是如何在订单提交后让程序减去库存。例如，当前数量为12，一旦我选择了餐1（鱼和薯条）并单击提交，我希望更新menu.xml文件以将数量显示为11.有人可以帮助我如何做到这一点

干杯。

我的menu.xml文件示例

<?xml version="1.0" encoding="utf-8"?>
<MenuInfo>
<Meal>
<MealID>1</MealID>
<Food>Meal 1 (Fish and Chips)</Food>
<Price>£4.99</Price>
<Time>25 minutes</Time>
<Quantity>12</Quantity>
</Meal>
<Meal>
<MealID>2</MealID>
<Food>Meal 2 (Chicken and Chips)</Food>
<Price>£3.99</Price>
<Time>25 minutes</Time>
<Quantity>12</Quantity>
</Meal>
<Meal>
<MealID>3</MealID>
<Food>Meal 3 (Saussage and Chips)</Food>
<Price>£2.99</Price>
<Time>25 minutes</Time>
<Quantity>12</Quantity>
</Meal>
<Meal>
<MealID>4</MealID>
<Food>Meal 4 (Burger and Chips)</Food>
<Price>£5.99</Price>
<Time>25 minutes</Time>
<Quantity>12</Quantity>
</Meal>
</MenuInfo>

Image of application

****** ****** UPDATE

 XDocument doc = XDocument.Load("order.xml");
        XElement root = new XElement("MenuInfo");

        foreach(DataGridViewRow dr in dataGridView.Rows)
        {
            if(dr.Selected)
            {
                root.Add(new XElement("Meal", dr.Cells["Food"].Value.ToString()));
                root.Add(new XElement("SeatID", _seat));
                root.Add(new XElement("TableID", buttonTable1.Text));
                root.Add(new XElement("Price", dr.Cells["Price"].Value.ToString()));
                doc.Element("Menu").Add(root);
                doc.Save("order.xml");
            }
        }

这是我的代码，用于当用户将订单提交到＆＃34; order.xml＆＃34;文件。对困惑感到抱歉。这完全基于Linq to XML

Answer 1

请看下面的代码 - 希望这是你想要的：

        XmlDocument doc = new XmlDocument();
        doc.LoadXml(@"<MenuInfo>
                            <Meal>
                            <MealID>1</MealID>
                            <Food>Meal 1 (Fish and Chips)</Food>
                            <Price>£4.99</Price>
                            <Time>25 minutes</Time>
                            <Quantity>12</Quantity>
                            </Meal>
                        </MenuInfo>");
        XmlNode node = doc.DocumentElement.SelectSingleNode("/MenuInfo/Meal/Quantity");            
        int qty = Convert.ToInt32(node.InnerText);

         // Deducting 1 from orginal quantity, you can use variable instead of quantity 1
        node.InnerText = (qty - 1).ToString();

        //Finally you can retrieve modified xml from using doc.InnerXml
        string modifiedXml = doc.InnerXml

Answer 2

假设您正在使用XmlDocument，您可以执行以下操作：

XmlDocument xml = new XmlDocument();

xml.LoadXml(@"
    <MenuInfo>
        <Meal>
            <MealID>1</MealID>
            <Food>Meal 1 (Fish and Chips)</Food>
            <Price>£4.99</Price>
            <Time>25 minutes</Time>
            <Quantity>12</Quantity>
        </Meal>
    </MenuInfo>");

// this selects the correct MealID and updates the quantity all in one go
xml.SelectSingleNode("/MenuInfo/Meal[MealID = '1']/Quantity").InnerText = "11";

从＆＃34; quantity＆＃34;节点中减去xml文件

2 个答案: