使用LINQ to XML访问值

Question

I am working on an XML format that is generated automatically by another application, and I want to traverse the XML using Linq to XML, but I'm not sure how to get the values I need.

Here is a snippet of the XML:

<dict>
<key>Major Version</key><integer>1</integer>    
<key>Tracks</key>
<dict>
    <key>3620</key>
    <dict>
        <key>Track ID</key><integer>3620</integer>
        <key>Name</key><string>Ran</string>
        <key>Age</key><integer>22</integer>         
    </dict>
    <key>3622</key>
    <dict>
        <key>Track ID</key><integer>3622</integer>
        <key>Name</key><string>Jardine</string>
        <key>Age</key><integer>24</integer>         
    </dict>

as you can see, dict is repeated internally, and the key and values are separated by individual nodes. I need to get dict nodes where their key age is greater than a value (or basically, I need to filter by a value under the dict )

Here's what I have got so far to get all Age values as a list:

        var ran = x.Root.Elements("dict")
                    .Elements("dict")
                    .Elements("dict")
                    .Select(r =>
                        r.Descendants("key")
                        .Where(w => w.Value == "Age")
                        .Select(s => (XElement)
                            s.NextNode
                            )
                    ).ToList();

Since the Key 's actual value is stored as a sibling node, I access those using NextNode .

However, that's where the problem is. How do I filter those XElements in the variable ran according to a condition, such as greater than a value?

I tried ran.Any and ran.Select but I'm not sure which lambda expression to use. Or should I append my filter in my original ran query?

Answer 1

Using ElementsAfterSelf.First() you can move on to the next XElement. This code is making a lot of assumptions that there will be another XElement and it will be the integer element and the value will be an int. You will need to decide how much you trust the other system is always sending you the XML in this format or if you need to write some defensive code.

var age = 23;

var ran = xdoc.Root.Elements("dict")
              .Elements("dict")
              .Elements("dict")
              .Elements("key")
              .Where(x => (string) x == "Age" && (int) x.ElementsAfterSelf.First() > age)
              .Select(x=>x.Parent);