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C# deserialize xml error ReadElementContentAs() methods cannot be called on an element that has child elements

I've looked at several similar SO questions but still can't solve my issue.
Using the following code I try to deserialize:
private static QCOrderInfo GetOrderFromXml(XDocument xmlDoc){
XmlSerializer serializer = new XmlSerializer(typeof(QCOrderInfo));
var post =
(QCOrderInfo)serializer.Deserialize(xmlDoc.Root.CreateReader());
return post ?? new QCOrderInfo();
}
The error resulting:
System.Xml.XmlException: ReadElementContentAs() methods cannot be called on an element that has child elements.
at System.Xml.XmlReader.SetupReadElementContentAsXxx(String methodName)
Too much code to post but view working dotnetfiddle:
https://dotnetfiddle.net/pRCWQh

Your appoved appraisers are not getting deserialized properly.
So add a class
[Serializable]
public class ApprovedAppraisers
{
[XmlElement(ElementName = "Appraiser")]
public string Appraiser { get; set; }
}
And change
public string[] ApprovedAppraisers { get; set; }
to
public ApprovedAppraisers[] ApprovedAppraisers { get; set; }

C# XML Serialization removing wrapper element

I wrote because I have problem with XmlSerializer. I want XML in the following format:
<?xml version="1.0" encoding="utf-8"?>
<RootXML>
<e-Invoice>
<Version>1.03</Version>
</e-Invoice>
<TradeInvoice>
<Id>1</Id>
<Value>100</Value>
</TradeInvoice>
<e-Invoice>
<Version>1.03</Version>
</e-Invoice>
<TradeInvoice>
<Id>2</Id>
<Value>200</Value>
</TradeInvoice>
<e-Invoice>
<Version>1.03</Version>
</e-Invoice>
<TradeInvoice>
<Id>3</Id>
<Value>300</Value>
</TradeInvoice>
</RootXML>
So I created the following classes.
[XmlRoot("RootXML")]
public class Root
{
public Root()
{
RootBodies = new List<RootBody>();
}
[XmlElement("e-Invoice")]
public List<RootBody> RootBodies { get; set; }
}
public class RootBody
{
public RootBody()
{
TradeInvoice = new TradeInvoice();
EInvoiceInfo = new Version(); ;
}
[XmlElement("e-Invoice")]
public Version EInvoiceInfo { get; set; }
[XmlElement("TradeInvoice")]
public TradeInvoice TradeInvoice { get; set; }
}
public class Version
{
[XmlElement("Version")]
public string Version { get; set; }
}
public class TradeInvoice
{
[XmlElement("Id")]
public int Id { get; set; }
[XmlElement("Value")]
public int Value { get; set; }
}
I have problem with removing wraper Elements (remove RootBody). I read similar topic like this link. But it does not solve my problem.

Before the actual explanation, let me point out a couple of very important things:
This XML is not very well designed and will cause a lot of other problems along the line (I'm guessing it is actually a lot more complicated than this).
The naming convention is inconsistent (e-Invoice and TradeInvoce)
The version number looks out of place, make sure this is really what they (whoever told you to do this) want before investing additional time.
This XML defines no namespaces (and probably doesn't have an XSD or DTD either)
Take a look at Google's XML design guidelines. You'll realize there is a lot of room for improvement.
There are a lot of different ways to do this, this is just one of them. I recommend you instead take it up with whoever is responsible for this design and try to change their mind.
Since you want to serialize e-Invoice and TradeInvoce without a wrapper element but still keep the order of elements (because they belong together) you need to make sure they have a common base class so they can be serialized from the same collection.
This abstract Invoice class simply tells the serializer which classes should be included during serialization via the XmlInclude attribute.
[XmlInclude(typeof(EInvoice))]
[XmlInclude(typeof(TradeInvoice))]
public abstract class Invoice
{
}
Your actual classes will be mostly unchanged
[XmlRoot("e-Invoice")]
public class EInvoice : Invoice
{
[XmlElement("Version")]
public string Version { get; set; }
}
[XmlRoot("TradeInvoice")]
public class TradeInvoice : Invoice
{
[XmlElement("Id")]
public int Id { get; set; }
[XmlElement("Value")]
public int Value { get; set; }
}
Your data class doesn't need any XML-related Attributes anymore because as it is now, it can't be serialized into that format directly.
public class InvoicePair
{
public InvoicePair(EInvoice eInvoice, TradeInvoice tradeInvoice)
{
TradeInvoice = tradeInvoice;
EInvoiceInfo = eInvoice;
}
public EInvoice EInvoiceInfo { get; set; }
public TradeInvoice TradeInvoice { get; set; }
}
Your Root class has to be simplified a bit. Since we want EInvoce and TradeInvoice Elements on the same level but mixed together, we need to put them in the same collection. The XmlElement attributes will tell the serializer how to handle elements of different types without relying on the xsi:type attribute.
[XmlRoot("RootXML")]
public class Root
{
public Root()
{
RootBodies = new List<Invoice>();
}
[XmlElement(Type = typeof(EInvoice), ElementName = "e-Invoice")]
[XmlElement(Type = typeof(TradeInvoice), ElementName = "TradeInvoice")]
public List<Invoice> RootBodies { get; set; }
}
Serialization is quite straight-forward at this point. Simply add all elements to the collection of elements one after another:
public static void Serialize(IEnumerable<InvoicePair> invoices, Stream stream)
{
Root root = new Root();
foreach (var invoice in invoices)
{
root.RootBodies.Add(invoice.EInvoiceInfo);
root.RootBodies.Add(invoice.TradeInvoice);
}
XmlSerializer serializer = new XmlSerializer(typeof(Root));
serializer.Serialize(stream, root);
}
Deserialization isn't very hard either, but very prone to erros and makes a lot of assumptions:
public static IEnumerable<InvoicePair> Deserialize(Stream stream)
{
XmlSerializer serializer = new XmlSerializer(typeof(Root));
Root root = serializer.Deserialize(stream) as Root;
for (int i = 0; i < root.RootBodies.Count; i += 2)
{
yield return new InvoicePair(
(EInvoice) root.RootBodies[i],
(TradeInvoice) root.RootBodies[i+1]
);
}
}
Here is a working Demo Fiddle, that outputs the XML

Omitting elementwrappers and getting the xml root value

<root xmlns:test="url" test:attr1="10" test:attr2="someValue>
<elementwrapper>
<secondElementwrapper>
<element>someValue</element>
<differentelement>anotherValue</differentelement>
</secondElementwrapper>
</elementwrapper>
</root>
The following classes are made:
public class XmlEntities
{
[XmlRoot("root")]
public class Root
{
[XmlElement("elementwrapper")]
public Elementwrapper Elementwrapper{ get; set; }
}
public class Elementwrapper
{
[XmlElement("secondElementwrapper")]
public SecondElementwrapper SecondElementwrapper{ get; set; }
}
public class Values
{
[XmlElement("element")]
public string Element{ get; set; }
[XmlElement("differentelement")]
public string Differentelement{ get; set; }
}
}
And here is where i serialize and deserialize the xml:
var reader = XmlReader.Create(url);
var xmlRecord = new XmlEntities.Root();
try
{
var serializer = new XmlSerializer(typeof(XmlEntities.Root));
xmlRecord = (XmlEntities.Root)serializer.Deserialize(reader);
reader.Close();
}
catch (Exception e) { }
I want to access xmlRecord.Element instead of xmlRecord.Elementwrapper.Values.Element
How do i get the test:attr1 value?*
If i remove the class Elementwrapper and Root, xmlRecord returns null.
[XmlAttribute] inside the Root class to get attr1 value doesnt work for me.
Thank you!
EDIT:
The element was a copy/paste wrong doing. Fixed that. I also added :test infront of the attr1, forgot that.
EDIT:
Adding the following as sgk mentioned, inside the root class, allowed me to access the attribute
[XmlAttribute("attr1", Namespace = "url")]
public string attr { get; set; }
EDIT: And is there a way to map the classes differently? So i can access xmlRecord.Element directly?
EDIT: #TonyStark seems like what i want needs to be approached a different way, but then again this already works i just need to access the element trough the nodes (xmlRecord.elementwrapper.secondelementwrapper.element) for those that are wondering.
To access the attribute of root i simply use : xmlRecord.attr after i added the xmlattribute that its written above.

I want to access xmlRecord.Element instead of xmlRecord.Elementwrapper.Values.Element - Based on the XML structure you have, to Deserialize and access the <element> value and <differentelement> value - you need to go through root-->elementwrapper-->secondElementwrapper.
How do i get the attr1 value? - add [XmlAttribute("attr1")] inside class Root
Then, [XmlElement("<elementwrapper>")] should be [XmlElement("elementwrapper")] otherwise when you Deserialize you will always get null as there is no matching element.
See below
public class XmlEntities
{
[XmlRoot("root")]
public class Root
{
[XmlElement("elementwrapper")]
public Elementwrapper Elementwrapper { get; set; }
[XmlAttribute("attr1", Namespace="url")]
public string attr1;
}
public class Elementwrapper
{
[XmlElement("secondElementwrapper")]
public SecondElementwrapper SecondElementwrapper { get; set; }
}
public class SecondElementwrapper
{
[XmlElement("element")]
public string Element { get; set; }
[XmlElement("differentelement")]
public string Differentelement { get; set; }
}
}

How to serialize the base class with derived classes

.
Hello,
I have this sample code :
public class Vehicule
{
public string Name { get; set; }
public Brand Brand { get; set; }
}
public class Car : Vehicule
{
public string Matriculation { get; set; }
}
public class Brand
{
public string Name { get; set; }
}
public class Renault : Brand
{
public string Information { get; set; }
}
If I create this instance :
var car = new Car { Name = "Clio", Matriculation = "XXX-XXX", Brand = new Renault { Name = "Renault", Information = "Contact Infos" } };
When I serialize this object like that :
var serializer = new XmlSerializer(typeof(Car), new Type[] { typeof(Renault)});
serializer.Serialize(wr, car);
I obtain this :
<?xml version="1.0" encoding="utf-8"?>
<Car xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Name>Clio</Name>
<Brand xsi:type="Renault">
<Name>Renault</Name>
<Information>Contact Infos</Information>
</Brand>
<Matriculation>XXX-XXX</Matriculation>
</Car>
But, in my project, I don't have to have informations on derived classes, I would like only elements of base classes from this instance like this :
var serializer = new XmlSerializer(typeof(Vehicule));
serializer.Serialize(wr, car);
The Xml :
<?xml version="1.0" encoding="utf-8"?>
<Vehicule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Name>Clio</Name>
<Brand>
<Name>Renault</Name>
</Brand>
</Vehicule>
Can you please, help me to obtain the good Xml (only with base type Vehicule and Brand) ?
Many thanks

You can't magically serialize a derived class as it's base because
"...Serialization checks type of instance by calling Object.getType()
method. This method always returns the exact type of object."
http://bytes.com/topic/net/answers/809946-how-force-serialize-base-type
The solution here, if you really need to only serialize the base class is to implement the IXmlSerializable interface and create your own custom serializer.
IXmlSerializable:
http://msdn.microsoft.com/en-us/library/system.xml.serialization.ixmlserializable(v=vs.110).aspx
One more thought. If you can work around the limitation of outputting the extra XML elements, you are able to serialize the derived class using only the base object by either 1) using XmlIncludeAttributes on the base class to tell it which types to expect or 2) using the XmlSerializer constructor overload that takes a list of types.
Edit:
After thinking about this a little more, a workaround would be that you would add a Clone() method onto your base object, then serialize the clone of the base.
LinqPad code:
public class Vehicule
{
public string Name { get; set; }
public Brand Brand { get; set; }
public Vehicule Clone()
{
return new Vehicule { Name = this.Name, Brand = new Brand { Name = this.Brand.Name } };
}
}
public class Car : Vehicule
{
public string Matriculation { get; set; }
}
public class Brand
{
public string Name { get; set; }
}
public class Renault : Brand
{
public string Information { get; set; }
}
void Main()
{
var car = new Car { Name = "Clio", Matriculation = "XXX-XXX", Brand = new Renault { Name = "Renault", Information = "Contact Infos" } };
var vehicle = car as Vehicule;
var serializer = new System.Xml.Serialization.XmlSerializer(typeof(Vehicule));
XmlWriterSettings settings = new XmlWriterSettings
{
Encoding = new UnicodeEncoding(false, false),
Indent = false,
OmitXmlDeclaration = false
};
using(StringWriter textWriter = new StringWriter())
using(XmlWriter xmlWriter = XmlWriter.Create(textWriter, settings)) {
serializer.Serialize(xmlWriter, vehicle.Clone());
textWriter.ToString().Dump();
}
}

This is one of the issues with inheritance, and another reason to favor composition imho.
I ran into the same issue on a mobile app where I had a Contact class that derives from ContactSummary. The repository returns Contact instances, but in lots of cases I only wanted the ContactSummary going over the wire to save on message sizes and data usage etc. The default Xml and Json serialisers would only work when the derived class was attributed with the [KnownType()] of the base class, but this still meant all those extra properties going over the wire.
Using inheritance it is problematic to achieve a viable solution, and I didn't want to resort to custom serialisers, and if the solution is to pollute the DTO with copy constructors and clone properties, then why not change the DTO to use composition instead?
If you have control over your DTOs, then restructuring them to use composition rather than inheritance may be the answer. In my example it was fairly simple...
public class ContactSummary
{
public string Name { get; set;}
public string Phone { get; set; }
}
public class Contact
{
public ContactSummary Summary { get; set; }
// ... other properties here
}
In your example, Car would need to contain a reference to Vehicle not inherit from it - something like...
[KnowTypes(typeof(Renault))]
public class Vehicle
{
public string Name { get; set; }
public Brand Brand { get; set; }
}
public class Car
{
public Vehicle Vehicle { get; set; }
public string Matriculation { get; set; }
}
Then when you want the 'base' type in your example, simply serialise Car.Vehicle.

I had the same problem and I got around it by re-mapping the inheriting class into the base class using AutoMapper:
MapperConfiguration config = new MapperConfiguration(cfg => cfg.CreateMap<Inheriting, Base>());
IMapper mapper = config.CreateMapper();
var baseObj = mapper.Map<Base>(InheritingObj);
There is not much you can customize on XmlSerializer out-of-the-box options.

Controlling XML Serialization of a List<> derived class

I'm converting a Dictionary object into a List<> derived class by means of the following two declarations:
[Serializable]
public class LogItem
{
public string Name { get; set; }
public string Value { get; set; }
public LogItem(string key, string value)
{
Name = key; Value = value;
}
public LogItem() { }
}
public class SerializableDictionary : List<LogItem>
{
public SerializableDictionary(Dictionary<string, string> table)
{
IDictionaryEnumerator index = table.GetEnumerator();
while (index.MoveNext())
{
Put(index.Key.ToString(), index.Value.ToString());
}
}
private void Put(string key, string value)
{
base.Add(new LogItem(key, value));
}
}
I intend to serialize SerializableDictionary by means of the following code:
SerializableDictionary log = new SerializableDictionary(contents);
using (StringWriter xmlText = new StringWriter())
{
XmlSerializer xmlFormat =
new XmlSerializer(typeof(SerializableDictionary), new XmlRootAttribute("Log"));
xmlFormat.Serialize(xmlText, log);
}
Works fine, but I'm unable to change the XML formatting.
This XML document is intended to be sent to a xml database field and is not meant to be deserialized.
I'd rather have both Name and Value
formatted as attributes of the
LogItem element.
However any attempts at using XMLAttribute have resulted in Reflection or compilation errors. I'm at loss as to what I can do to achieve this requirement. Could someone please help?

you can annotate them with XmlAttribute:
[Serializable]
public class LogItem
{
[XmlAttribute]
public string Name { get; set; }
[XmlAttribute]
public string Value { get; set; }
public LogItem(string key, string value)
{
Name = key; Value = value;
}
public LogItem() { }
}
This worked fine for me and produced the following XML (based on sample input):
<?xml version="1.0" encoding="utf-16"?>
<Log xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<LogItem Name="foo" Value="bar" />
<LogItem Name="asdf" Value="bcxcvxc" />
</Log>

There must be something else going on besides what you are showing. I am able to compile and execute the above code both with and without the XmlAttribute attribute applied to the Name and Value properties.
[XmlAttribute]
public string Name { get; set; }
[XmlAttribute]
public string Value { get; set; }