Develop Reference

C# XElement how do I add different attributes in a specific order?

I have the following C# code to generate an XML document. The problem is that I need to swap the order of the attributes in the tag "CState". Therefore I have already tried several things. Unfortunately it does not work or I get an exception.
XNamespace ns = "http:dev.test.com/Job/Con";
XNamespace nsi = "http:www.w3.org/2001/XMLSchema-instance";
XElement doc = new XElement(ns + "CState", new XAttribute(XNamespace.Xmlns + "xsi", nsi),
new XElement(ns + "Page",
new XElement(ns + "Field", new XAttribute("dName", "MembershipNumber"), new XAttribute("type", "Text"), new XAttribute("value", "123456")),
new XElement(ns + "Field", new XAttribute("dName", "FirstName"), new XAttribute("type", "Text"), new XAttribute("value", "Michael")),
new XElement(ns + "Field", new XAttribute("dName", "LastName"), new XAttribute("type", "Text"), new XAttribute("value", "Hendly"))
));
This is the output in the XML file.
<?xml version="1.0" encoding="utf-8"?>
<CState xmlns:xsi="http:www.w3.org/2001/XMLSchema-instance" xmlns="http:dev.test.com/Job/Con">
<Page>
<Field dName="MembershipNumber" type="Text" value="123456" />
<Field dName="FirstName" type="Text" value="Michael" />
<Field dName="LastName" type="Text" value="Hendly" />
</Page>
</ControlStatements>
However, the attributes should appear in a different order.
This is how the second line in the XML file is created (incorrect):
<CState xmlns:xsi="http:www.w3.org/2001/XMLSchema-instance" xmlns="http:dev.test.com/Job/Con">
This is how the second line should be created in the XML file (correct):
<CState xmlns="http:dev.test.com/Job/Con" xmlns:xsi="http:www.w3.org/2001/XMLSchema-instance">
How can I achieve this as easily as possible?

C# XML-Serialization of various subitems in list as xml attributes

I am trying to create a generic class structure to save lists with various subitems in an xml file as XML attributes. Each subitem has Name (string) and a Value (double).
An example:
The XML of two Lists - frame 1 and frame 2 - should look like this shown above. The frame1 is a List of the class rec. The class rec always contains multiple pairs of parameters and their values. In frame1 the class rec contains the parameters car, factory and height. And in frame2 book and page.
<frame1>
<rec car="0" factory="1" height="2" />
<rec car="1" factory="4" height="2" />
<rec car="2" factory="4" height="3" />
<rec car="3" factory="5" height="2" />
</frame1>
<frame2>
<rec book="0" page="1" />
<rec book="1" page="4" />
<rec book="2" page="4" />
<rec book="3" page="5" />
</frame2>
This is only an example. I do not want to create different classes with different properites for each "frame" List. I want to solve the problem with one class "rec" as the subitems are always changing. Is there a way to create this?
Thank you in advance

I think you can use a code like this: lists is an object[][], so not any generic types needed.
using System.Xml.Linq;
...
var lists = new[]
{
new object[]
{
new ClassA("0", "1", "2"), new ClassA("1", "4", "2"), new ClassA("2", "4", "3"),
new ClassA("3", "5", "2"),
},
new object[]
{
new ClassB("0", "1"), new ClassB("1", "4"), new ClassB("2", "4"),
new ClassB("3", "5"),
}
};
var xml = new XDocument(new XElement("Root"));
for (var i = 0; i < lists.Length; i++)
{
var eFrame = new XElement($"frame{i}");
var list = lists[i];
foreach (var obj in list)
{
var eRec = new XElement("rec");
var props = obj.GetType().GetProperties();
foreach (var prop in props)
{
eRec.SetAttributeValue(prop.Name, prop.GetValue(obj).ToString());
}
eFrame.Add(eRec);
}
xml.Root.Add(eFrame);
}
Result will be something like this as xml object:
<Root>
<frame0>
<rec car="0" factory="1" height="2" />
<rec car="1" factory="4" height="2" />
<rec car="2" factory="4" height="3" />
<rec car="3" factory="5" height="2" />
</frame0>
<frame1>
<rec book="0" page="1" />
<rec book="1" page="4" />
<rec book="2" page="4" />
<rec book="3" page="5" />
</frame1>
</Root>

insert new node with its attribute to xml

I have the following xml node
<group>
<level id="1" name="Level 1" />
<level id="2" name="Level 2" />
</group>
How can insert new element with it's attributes to xml file

var doc = XDocument.Load("yourxmlfile.xml");
var x = new XElement("level",
new XAttribute("id", 3),
new XAttribute("name", "Level 3"));
doc.Element("group").Add(x);
doc.Save("yourxmlfile.xml");

Cant add data to xml from list using linq

This code doesn't work for me and I can't understand why.
xmlDoc.Element("results").Add(
new XElement("user",
new XAttribute("id", user.Id),
new XAttribute("facebookid", user.FacebookId),
new XAttribute("email", user.Email),
new XAttribute("totalpoints", totalpoints)
).Add(
user.Answers.Select(value => new XElement("question",
new XAttribute("id", value.QuestionId),
new XAttribute("answer_id", value.AnswerId),
new XAttribute("points", value.Points)))
)
);
I'm trying to create this
<results>
<user id="2323" facebookId="3254954795743957" email="david#gmail" totalPoints="">
<question id="1" answer_id="3" points="0" />
<question id="2" answer_id="1" points="1" />
</user>
</results>

xmlDoc.Element("results").Add(
new XElement("user",
new XAttribute("id", user.Id),
new XAttribute("facebookid", user.FacebookId),
new XAttribute("email", user.Email),
new XAttribute("totalpoints", totalpoints),
user.Answers.Select(value => new XElement(
"question",
new XAttribute("id", value.QuestionId),
new XAttribute("answer_id", value.AnswerId),
new XAttribute("points", value.Points)
))
)
);
The problem was that the Add method returns void so you can't continue with another Add over the void result. Also, for attributes you need to use XAttribute, not XElement.

How to perform a hierarchical LINQ to XML query?

I know I can do this iteratively, but it would be cool to do it in a single LINQ statement.
I have some XML that looks like this:
<parent name="george">
<child name="steve" age="10" />
<child name="sue" age="3" />
<pet type="dog" />
<child name="jill" age="7" />
</parent>
<!-- ... -->
and I want to write a LINQ to XML statement to turn it into
<node type="parent" label="george">
<node type="child" label="steve" years="10 />
<node type="child" label="sue" years="3" />
<node type="child" label="jill" years="7" />
<!-- no pets! -->
</parent>
<!-- ... -->
Is that possible in a single LINQ to XML statement?
I've included two from statements in a LINQ statement before, but not a second select, which seems to be what this would require.

You'll need to query the desired elements and create new elements and attributes using the queried items. Something like this should work:
var input = #"<root>
<parent name=""george"">
<child name=""steve"" age=""10"" />
<child name=""sue"" age=""3"" />
<pet type=""dog"" />
<child name=""jill"" age=""7"" />
</parent>
</root>";
var xml = XElement.Parse(input);
var query = from p in xml.Elements("parent")
select new XElement("node",
new XAttribute("type", p.Name),
new XAttribute("label", p.Attribute("name").Value),
from c in p.Elements("child")
select new XElement("node",
new XAttribute("type", c.Name),
new XAttribute("label", c.Attribute("name").Value),
new XAttribute("years", c.Attribute("age").Value)));

Quick and dirty:
doc.Elements("parent")
.Select(p =>
new XElement("node",
new XAttribute("type", p.Name),
new XAttribute("label", p.Attribute("name") != null ? p.Attribute("name").Value : ""),
p.Elements("child")
.Select(c =>
new XElement("node",
new XAttribute("type", c.Name),
new XAttribute("label", c.Attribute("name") != null ? c.Attribute("name").Value : ""),
new XAttribute("years", c.Attribute("age") != null ? c.Attribute("age").Value : ""))
)
)
);