DataGrid更新XML属性时批量赋值异常的排查与修复请求

通过GetProductsPriceList()方法从XML文件读取指定节点属性并加载到DataGrid，编辑Visible和Price列后保存回XML时，所有产品的这两个属性被设置为同一个值。调试时pp.Visible和pp.Price的内容正确，但循环写法有误，需要修复以实现每个产品对应更新XML中属性。

读取数据的代码：

private ObservableCollection<Products> GetProductsPriceList()
{
    productpricelist = new ObservableCollection<Products>();
    XmlDocument doc = new XmlDocument();
    doc.Load(@"C:\xmltest\26112023.txt");
    foreach (XmlElement pn in doc.SelectNodes("/Data/Products/*"))
    {
        var productlist = new Products
        {
            Mainproduct = pn.LocalName.ToString(),
            Name = pn.GetAttribute("Name"),
            Price = pn.SelectSingleNode(".//ProductPrice/@Price")?.Value,
            Visible = pn.SelectSingleNode(".//ProductVisibility/@Visible")?.Value,
            NameIcon = pn.GetAttribute("DefaultIconName")
        };
        productpricelist.Add(productlist);
    }

    return productpricelist;
}

原始保存代码：

private void Execute(object parm) //method to save back to the xml file price & visible attributes for each products 
{

    XmlDocument doc = new XmlDocument();
    doc.Load(@"C:\xmltest\26112023.txt");
    foreach (Products pp in productpricelist)
    {
        foreach (XmlElement pn in doc.SelectNodes("/Data/Products/*"))
        {

            foreach (XmlNode visibility in pn.SelectNodes("Visibilities"))
            {
                foreach (XmlNode productVisibilty in visibility.SelectNodes("ProductVisibility"))
                {
                    productVisibilty.Attributes["Visible"].InnerText = pp.Visible;

                    foreach (XmlNode price in productVisibilty.SelectNodes("Prices"))
                    {
                        foreach (XmlNode productPrice in price.SelectNodes("ProductPrice"))
                        {
                            productPrice.Attributes["Price"].InnerText = pp.Price;
                        }
                    }
                }
            }
        }

    }
doc.Save(@"C:\xmltest\26112023_.txt");
}

XML示例片段：

<?xml version="1.0" encoding="utf-8"?>
<Data>
  <ShippingMethodsReferences />
  <Products>
    <ProductApple ID="77f9df03-7525-44d7-b08d-dcf106b44969" Sys_Type="Library.Domain.Products.ProductApple" Sys_ImportStrategy="UpdateOnly" DefaultIconName="Xerox_10x8x2_R_Sticker.png" Profile="Fruits" DefaultOutputProfileTypeFullName="Output" Name="(10x8)x2 H Rectangular">
      <ShippingMethodPrices ImportStrategy="Replace" />
      <Visibilities ImportStrategy="Replace">
        <ProductVisibility ID="adfa5eca-3f58-4107-8738-5b9b1c0b666f" Visible="True">
          <Prices ImportStrategy="Replace">
            <ProductPrice ID="e558ceed-1e64-4540-8958-0203fea2b53b" Price="0" />
          </Prices>
        </ProductVisibility>
      </Visibilities>
    </ProductApple>
    <ProductSolo ID="7c1302d8-8832-451b-be64-c5d048d0332f" Name="(10x8)x2 H Rectangular">
      <Visibilities ImportStrategy="Replace">
        <ProductVisibility ID="078f6e6a-895c-4957-b808-2b38589ba4cd" Visible="True">
          <Prices ImportStrategy="Replace">
            <ProductPrice ID="0c14f953-9f75-4e24-9c38-245027107167" Price="0" />
          </Prices>
        </ProductVisibility>
      </Visibilities>
    </ProductSolo>
  </Products>
</Data>

原始保存代码中，外层遍历每个Products对象时，内层又遍历XML中所有产品节点，导致每次循环都会把所有XML产品的Visible和Price属性替换为当前pp的值。最终所有产品的属性会被最后一个pp的值覆盖。

核心思路：为每个Products对象找到XML中对应的产品节点（通过Mainproduct属性匹配节点名称），仅更新该节点下的属性：

private void Execute(object parm)
{
    XmlDocument doc = new XmlDocument();
    doc.Load(@"C:\xmltest\26112023.txt");
    
    foreach (Products pp in productpricelist)
    {
        // 找到当前产品对应的XML节点（通过节点名称匹配Mainproduct）
        XmlElement productNode = doc.SelectSingleNode($"/Data/Products/{pp.Mainproduct}") as XmlElement;
        if (productNode == null)
            continue; // 如果找不到对应节点，跳过
        
        // 更新Visible属性
        XmlNode visibilityNode = productNode.SelectSingleNode(".//ProductVisibility");
        if (visibilityNode != null && visibilityNode.Attributes["Visible"] != null)
        {
            visibilityNode.Attributes["Visible"].InnerText = pp.Visible;
        }
        
        // 更新Price属性
        XmlNode priceNode = productNode.SelectSingleNode(".//ProductPrice");
        if (priceNode != null && priceNode.Attributes["Price"] != null)
        {
            priceNode.Attributes["Price"].InnerText = pp.Price;
        }
    }
    
    doc.Save(@"C:\xmltest\26112023_.txt");
}

1. 使用SelectSingleNode结合pp.Mainproduct直接定位到对应产品节点，避免遍历所有节点
2. 增加空值判断，防止节点或属性不存在时引发异常
3. 简化嵌套循环，提升代码可读性和执行效率

内容的提问来源于stack exchange，提问作者user838691