Linq to xml using ASP.Net

本文关键字：ASP Net using xml to Linq | 更新日期: 2023-09-27 18:08:35

我试图将订单的所有元素填充到列表框中。列表框只添加集合，而不添加元素。请帮助!

XDocument doc = XDocument.Load(Server.MapPath("App_Data/Orders.xml"));
        string order = ddl.SelectedValue;
        var results = doc.Descendants("Order").Where(o => o.Attribute("OrderNumber").Value == "SO43659")
                         .Select(o => o.Elements("LineItem"));
        foreach (var r in results)
        {
          ListBox1.Items.Add(new ListItem(r.ToString()));
        }

xml片段:

<Order OrderNumber="SO43659">
    <LineItem Line="1" PID="349" Qty="1" Price="2024.9940" Freight="50.6249" />
    <LineItem Line="2" PID="350" Qty="3" Price="2024.9940" Freight="151.8746" />
    <LineItem Line="3" PID="351" Qty="1" Price="2024.9940" Freight="50.6249" />
    <LineItem Line="4" PID="344" Qty="1" Price="2039.9940" Freight="50.9999" />
    <LineItem Line="5" PID="345" Qty="1" Price="2039.9940" Freight="50.9999" />
    <LineItem Line="6" PID="346" Qty="2" Price="2039.9940" Freight="101.9997" />
    <LineItem Line="7" PID="347" Qty="1" Price="2039.9940" Freight="50.9999" />
    <LineItem Line="8" PID="229" Qty="3" Price="28.8404" Freight="2.1630" />
    <LineItem Line="9" PID="235" Qty="1" Price="28.8404" Freight="0.7210" />
    <LineItem Line="10" PID="218" Qty="6" Price="5.7000" Freight="0.8550" />
    <LineItem Line="11" PID="223" Qty="2" Price="5.1865" Freight="0.2593" />
    <LineItem Line="12" PID="220" Qty="4" Price="20.1865" Freight="2.0187" />
  </Order>

Linq to xml using ASP.Net

var results = doc.Descendants("Order")
                 .Where(o => o.Attribute("OrderNumber").Value == "SO43659")
                 .FirstOrDefault();
foreach (var r in results.Elements("LineItem"))
{
    ListBox1.Items.Add(new ListItem(r.ToString()));
}

如果您不使用var，您会看到什么是错误的- results的每个元素是一个元素序列。下面是没有var的代码:

IEnumerable<IEnumerable<XElement>> results =
   doc.Descendants("Order")
      .Where(o => o.Attribute("OrderNumber").Value == "SO43659")
      .Select(o => o.Elements("LineItem"));
foreach (IEnumerable<XElement> r in results)
{
    ListBox1.Items.Add(new ListItem(r.ToString()));
}

我怀疑那不是你想要的。你可以用这个代替:

// Will go bang if there isn't exactly one matching order
IEnumerable<XElement> results =
   doc.Descendants("Order")
      .Where(o => o.Attribute("OrderNumber").Value == "SO43659")
      .Single()
      .Select(o => o.Elements("LineItem"));

或:

// Will find *all* the LineItem elements under *all* matching orders
IEnumerable<XElement> results =
   doc.Descendants("Order")
      .Where(o => o.Attribute("OrderNumber").Value == "SO43659")
      .SelectMany(o => o.Elements("LineItem"));
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