Linq to XML 嵌套查询

Question

我在使用 LINQ 查询时遇到问题。我有这个 XML：

<devices> 
   <device id ="2142" name="data-switch-01">
     <interface id ="2148" description ="Po1"/>
   </device>
   <device id ="2302" name="data-switch-02">
     <interface id ="2354" description ="Po1"/>
     <interface id ="2348" description ="Gi0/44" />
   </device>
 </devices>

和这个代码：

var devices = from device in myXML.Descendants("device")
              select new
              {
                  ID = device.Attribute("id").Value,
                  Name = device.Attribute("name").Value,
               };

foreach (var device in devices)
{
    Device d = new Device(Convert.ToInt32(device.ID), device.Name);

    var vIfs = from vIf in myXML.Descendants("device")
                  where Convert.ToInt32(vIf.Attribute("id").Value) == d.Id
                  select new
                  {
                      ID = vIf.Element("interface").Attribute("id").Value,
                      Description = vIf.Element("interface").Attribute("description").Value,
                  };
    foreach (var vIf in vIfs)
    {
        DeviceInterface di = new DeviceInterface(Convert.ToInt32(vIf.ID), vIf.Description);
        d.Interfaces.Add(di);
    }

    lsDevices.Add(d);
}

我的设备对象包含我需要从 XML 填充的设备接口列表。目前我的代码仅填充第一个界面，任何后续界面都会被忽略，我不明白为什么。

我也很感激任何关于这是否是正确方法的评论。嵌套的 foreach 循环对我来说似乎有点混乱

干杯

Answer 1

IEnumerable<Device> devices = 
  from device in myXML.Descendants("device")
  select new Device(device.Attribute("id").Value, device.Attribute("name").Value)
  {
     Interfaces = (from interface in device.Elements("Interface")
                   select new DeviceInterface(
                        interface.Attribute("id").Value,
                        interface.Attribute("description").Value)
                  ).ToList() //or Array as you prefer
  }

这里的基本点是，您在设备（它是后代）上执行某种“子选择”，查找它包含的所有Interface元素。

它为每个设备下的每个“接口”创建一个新的DeviceInterface。

Answer 2

又快又脏

var query = from device in document.Descendants("device")
            select new
            {
                ID = device.Attribute("id").Value,
                Name = device.Attribute("name").Value,
                Interfaces = from deviceInterface in device.Descendants("interface")
                             select new
                             {
                                 ID = deviceInterface.Attribute("id").Value,
                                 Description = deviceInterface.Attribute("description")
                             }
            };