如何编写单个LINQ to XML查询以遍历所有子元素和子元素的所有属性？

Question

I am developing asp.net mobile application. I am using XML as a database. I am querying on the XML to access the required elements & attributes by using LINQ to XML in .net. I have the follwing part in my XML file.

<VALVES>
     <VALVE NAME="PWV">
      <DISPLAY-NAME>
       Production Master Valve
      </DISPLAY-NAME>
      <COMMANDS USE-TEMPLATE="TRUE" TEAMPLATE-NAME="ValveCommands.xml"></COMMANDS>
    </VALVE>
    <VALVE NAME="PMV" >
     <DISPLAY-NAME>
      Production Wing Valve
     </DISPLAY-NAME>
     <COMMANDS USE-TEMPLATE="TRUE" TEAMPLATE-NAME="ValveCommands.xml"></COMMANDS>
    </VALVE>
</VALVES>

In the above XML file I can access the the child element node 'VALVE' & its attribute 'NAME' dynamically without explicitly specifying the name of the attribute by using following code. Thus as any new attribute is added in the child node 'VALVE' I can access it without modifying my existing code. For such logic I am using following code. In the following code ValvesProperties is the Hashtable which is defined in the class 'Valves'.

 static int count = 0;
 List<Valves> LstValves = new List<Valves>();

 string AttName = null;
 string AttValue = null;

 XDocument FieldDef = XDocument.Load(@"F:\Shailesh from user OPC\XML\KK3.xml");
 XElement FieldRoot = FieldDef.Element("KK");

 count = FieldRoot.Element("FIELD-DEFINITION").Element("VALVES").Elements("VALVE").Count();
 Valves[] Valveobj = new Valves[count];

 count = 0;

 foreach (var element in FieldRoot.Element("FIELD-DEFINITION").Element("VALVES").Elements())
 {
     Valveobj[count] = new Valves();

     foreach (var attribute in element.Attributes())
     {
         AttName = attribute.Name.ToString();
         AttValue = attribute.Value.ToString();
         Valveobj[count].ValvesProperties.Add(AttName, AttValue);
         LstValves.Add(Valveobj[count]);
     }

     count++;
  }

return LstValves;

The similar logic I need for the above defined XML part. In the above XML I want to write the LINQ to XML query which can access the NAME attribute of the 'VALVE' node ( <VALVE NAME="PWV"> ), then it should access the text between 'DISPLAY-NODE' ( <DISPLAY-NAME> Production Master Valve </DISPLAY-NAME> ), & then it should access the all the attributes of the 'COMMAND' node dynamically ( <COMMANDS USE-TEMPLATE="TRUE" TEAMPLATE-NAME="ValveCommands.xml"></COMMANDS> ). All these I want dynamically without explicitly specifying the name of the child node as well as name of their attributes ( similar to the way I written the above query ) Can we write such a code by using LINQ to XML ? It will be better if we can write code for above issue in a single logic ( similar to the way I written the above query ). Can you provide me the any code or link through which I can resolve the above issue ?

Answer 1

You could just iterate through all the elements and retrieve the attributes for each:

var allDescendants = myElement.DescendantsAndSelf();
var allDescendantsWithAttributes = allDescendants.SelectMany(elem =>
    new[] { elem }.Concat(elem.Attributes().Cast<XContainer>()));

foreach (XContainer elementOrAttribute in allDescendantsWithAttributes)
{
    // ...
}