在XDocument中搜索特定的节点值

Question

As my XML getting larger and larger. I am trying to find ways to search my XML even faster. I have read about this XDocument compared that this is much faster than XMLDocument but I am unable to know if this is true as I am not familiar with XML.Linq syntax.

This is my sample XML.

<?xml version="1.0" encoding="utf-8"?>
<Application>
    <Library>
        <Track>
            <TrackID>1</TrackID>
            <Name>Sample</Name>
            <Artist>ArtistName</Artist>
            <Location>C:\Users\User\Music\01 File.m4a</Location>
        </Track>
        ...
    <Library>
</Application>

This is how I search a specific TrackID in my XML.

Dim nodeList As XmlNodeList = Document.SelectNodes("/iTunesCrimson/Library/Track"), trackID As Integer = 0
            For Each n As XmlNode In nodeList
                If Not track.Location = "" AndAlso n.SelectSingleNode("Location").InnerText = track.Location Then
                    trackID = Integer.Parse(n.SelectSingleNode("TrackID").InnerText)
                    Exit For
                End If
            Next
        Return trackID

And this is how I change the value of a specific node.

Document.SelectSingleNode("/Application/Library/Track[TrackID=" & TrackID & "]/Name").InnerText = "Sample Value"

I am having a hard time figuring out how Linq syntax works as I had a hard time learning XMLDocument . Can someone help me convert these functions into Linq for XDocument as I am not familiar with it at the moment.

My sample code is in VB.Net but C# will do.

I saw this here and I tried but gives me a NullReferenceException .

string id = "123"; // id to be selected

XElement Contact = (from xml2 in XMLDoc.Descendants("Node")
                    where xml2.Element("ID").Value == id
                    select xml2).FirstOrDefault();

Console.WriteLine(Contact.ToString());

Answer 1

If you want to search the Track node which contains some specific TrackId, you can use this:-

var result = xdoc.Descendants("Track")
                             .FirstOrDefault(x => (string)x.Element("TrackID") == id);

Here, xdoc is XDocument object: XDocument xdoc = XDocument.Load(YourXMLFile);

If you are looking to find and update the TrackID you can do it like this:-

xdoc.Descendants("Track").FirstOrDefault(x => (string)x.Element("TrackID") == id)
                         .SetElementValue("TrackID", "2");

Finally save your XML:-

xdoc.Save(YourXMLfile);