This question already has answers here:
Why doesn't XmlSerializer support Dictionary?
(3 answers)
Closed 9 years ago.
i'm using this class
public class Branch
{
public string Name { get; set; }
public User Manager { get; set; }
public User Secretary { get; set; }
public Dictionary<string, User> Broker;
public Dictionary<string, Apartment> Apartments;
public Branch()
{}
public Branch(Branch other)
{
Name = other.Name;
Manager = other.Manager;
Secretary = other.Secretary;
Broker = other.Broker;
Apartments = other.Apartments;
}
}
trying to run this line : Dict2XML.Save_Branch2XML(Branchs);
through this method:
static public void Save_Branch2XML(Dictionary<string, Branch> D)
{
//List<KeyValuePair<string, User>> DictionList = D.ToList();
List<Branch> DictionList = D.Select(p => new Branch(p.Value)).ToList<Branch>();
XmlSerializer Serializer = new XmlSerializer(DictionList.GetType());
TextWriter writer = new StreamWriter(#"C:\Users\tzach_000\Documents\Visual Studio 2013\Projects\RealEstate\RealEstate\DB\XMLBranch.xml");
Serializer.Serialize(writer, DictionList);
writer.Close();
}
and the program collapse when it gets to the XmlSerializer line in save_branch2xml method.
The XmlSerializer doesn't support dictionaries, I don't think it changed for all these years. There are multiple workarounds, two of them could be recommended.
First, change the internal data structure for one that is serializable. A list of pairs would do.
Second, use the DataContractSerializer rather than the xml serializer. The data contract serializer supports serialization of dictionaries.
See this thread
Serialize Class containing Dictionary member
You can use SerializableDictionary if you really want.
Related
In my application I use the following code to serialze objects:
private static string Serialize(Type type, object objectToSerialize)
{
StringBuilder builder = new StringBuilder();
using (TextWriter writer = new StringWriter(builder))
{
XmlSerializer serializer = new XmlSerializer(type);
serializer.Serialize(writer, objectToSerialize);
}
return builder.ToString();
}
This code just worked fine until now.
We've introduced a new class which looks like:
[Serializable]
public class Restriction
{
public string Id { get; set; }
public ResticType Type { get; set; }
public Restriction Parent { get; set; }
public List<Restriction> Children { get; set; }
}
If I try to serialize it I get the following exception:
A circular reference was detected while serializing an object of type Restriction
I already found out, that this occures because of the Parent and the Children which are also of type Restriction
I've already tried to set the Parent-Property to NonSerialized but this doesn't work.
Unfortunately I can not change the code for serialization...
What can I do to serialize this class?
Actual my only idea is to implement IXmlSerializable in my Restriction-class and do the reading and writing of the xml by my own. I hope there is another way...
I've already tried to set the Parent-Property to NonSerialized but this doesn't work.
NonSerialized is for binary serialization. Use XmlIgnore instead.
Note that you'll have to manually restore the Parent property after deserialization:
void RestoreParentRelationship(Restriction restriction)
{
foreach (var child in restriction.Children)
child.Parent = restriction;
}
This question already has answers here:
Json.net serialize specific private field
(2 answers)
JSON.net: how to deserialize without using the default constructor?
(6 answers)
Json.Net - Explicitly include a single private property
(1 answer)
Closed 4 years ago.
I have a class property set, and fixed in the constructor, example below is a Guid.NewGuid()..
The rationale being to only allow the class to populate, on creation.. so it's set in the constructor, and marked only as get; - works fine, until i serialize / deserialize to Json.
It seems that because there is no set; the deserialization fails.. and the constructor steps in and creates a new guid
I have tried internal, private, and protected set .. but all result in a regeneration of the property, the only way i can get it to work is by marking Id as {get;set;},
class Foo
{
public Foo() => Id = Guid.NewGuid().ToString();
public string Id { get; set; }
}
which then means you can simply do:
var obj = new Foo();
obj.Id = "Any Old Rubbish";
Is there a way around this at all?
Short sample:
class Program
{
static void Main()
{
var obj = new Foo();
Console.WriteLine(obj.Id);
var serialize = JsonConvert.SerializeObject(obj);
var deserialize = JsonConvert.DeserializeObject<Foo>(serialize);
Console.WriteLine(deserialize.Id);
Console.ReadLine();
}
}
class Foo
{
public Foo() => Id = Guid.NewGuid().ToString();
public string Id { get; }
}
Output:
7868a298-f20d-4719-85ef-ba64c8658819
34fe422c-9555-4d17-ae1a-9fbf21af1b71
The following image (it is not done by me but is found in this question) shows how the algorithm for JsonConvert.DeserializeObjectworks. As you can see the constructor of the serialized type is called almost always. That's why you have to use a constructor with parameters as the left most path of the image shows.
The following shows a modification of your example using a constructor with parameters.
class Program
{
static void Main()
{
var obj = new Foo(Guid.NewGuid().ToString());
Console.WriteLine(obj.Id);
var serialize = JsonConvert.SerializeObject(obj);
var deserialize = JsonConvert.DeserializeObject<Foo>(serialize);
Console.WriteLine(deserialize.Id);
Console.ReadLine();
}
}
class Foo
{
public Foo(String Id) => this.Id = Id;
public string Id { get; }
}
This will result in having the same guid before and after serialization while there is no need to use public string Id { get; set;} as you didn't want to.
The field is used only during the serialization / deserialization process but I would like to immediately encapsulate it and hide from the class.
Is it possible?
Basically, no.
XmlSerializer only works with public members, so you can't make it internal or private. You can add some attributes to make it less glaring especially in UIs that data-bind:
[Browsable(false)]
[EditorBrowsable(EditorBrowsableState.Never)]
public int Foo {get; set; }
but that only masks it. You could also look at IXmlSerializable, but that is a horrible API and most implementations of it are simply buggy - I do not recommend implementing this interface.
But: best practice is that whenever serialization requirements conflict with your model's design: create a dedicated DTO model - one that matches perfectly your chosen serialization library and exists purely for that purpose. And then map between the two. Then you don't have to compromise.
Its not possible with XML-Serialization in C# , if you want to do like that than you should make use of DataContractSerialization, It allows this kind of functionality i.e. you can serialize private field of you object.
Below is possible with DataContractSerialization, I hope you like to try out
[DataContract]
class Person
{
[DataMember]
public string m_name;
[DataMember]
private int m_age;
}
This what I tried when I was learning XML to Linq , and this is wired solution but if you want to try , here i created xml string by using xml to linq
here is my article : Object to XML using LINQ or XmlSerializer
Note : here code field of product class is private field but still you can generate xml string
using System.Collections.Generic;
using System.Xml.Linq;
using System.Linq;
class Program
{
public class Product
{
public Product()
{ }
public Product(string name,int code, List<productType> types)
{
this.Name = name;
this.Code = code;
this.types = types;
}
public string Name { get; set; }
private int Code { get; set; }
public List<productType> types { get; set; }
public string Serialize(List<Product> products)
{
XElement productSer = new XElement("Products",
from c in products
orderby c.Code
select new XElement("product",
new XElement("Code", c.Code),
new XElement("Name", c.Name),
new XElement("Types", (from x in c.types
orderby x.type//descending
select new XElement("Type", x.type))
))
);
return productSer.ToString();
}
}
public class productType
{
public string type { get; set; }
}
public static void Main()
{
List<productType> typ = new List<productType>();
typ.Add((new productType() { type = "Type1" }));
typ.Add((new productType() { type = "Type2" }));
typ.Add((new productType() { type = "Type3" }));
List<Product> products =new List<Product>() { new Product ( "apple", 9,typ) ,
new Product ("orange", 4,typ ),
new Product ("apple", 9 ,typ),
new Product ("lemon", 9,typ ) };
Console.WriteLine(new Product().Serialize(products));
Console.ReadLine();
}
}
Assuming you are using XmlSerializer, then only public fields and properties can be serialized, as explained in Troubleshooting Common Problems with the XmlSerializer:
The serializer examines all public fields and properties of the Type to learn about which types an instance references at runtime. It then proceeds to create C# code for a set of classes to handle serialization and deserialization using the classes in the System.CodeDOM namespace.
So, what are your options? If you are able to construct your XmlSerializer directly, you could make use of the XmlSerializer.UnknownElement event to forward the unknown elements to the object being deserialized for processing.
First, define the following attribute and extension methods:
[System.AttributeUsage(System.AttributeTargets.Method, AllowMultiple = false)]
public class XmlUnknownElementEventHandlerAttribute : System.Attribute
{
}
public static partial class XmlSerializationHelper
{
public static T LoadFromXml<T>(this string xmlString, XmlSerializer serial = null)
{
serial = serial ?? new XmlSerializer(typeof(T));
serial.UnknownElement += UnknownXmlElementEventHandler;
using (StringReader reader = new StringReader(xmlString))
{
return (T)serial.Deserialize(reader);
}
}
public static void UnknownXmlElementEventHandler(object sender, XmlElementEventArgs e)
{
var obj = e.ObjectBeingDeserialized;
foreach (var method in obj.GetType().BaseTypesAndSelf()
.SelectMany(t => t.GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly))
.Where(m => Attribute.IsDefined(m, typeof(XmlUnknownElementEventHandlerAttribute))))
{
method.Invoke(obj, BindingFlags.Public | BindingFlags.NonPublic, null, new object[] { sender, e }, null);
}
}
}
public static class TypeExtensions
{
public static IEnumerable<Type> BaseTypesAndSelf(this Type type)
{
while (type != null)
{
yield return type;
type = type.BaseType;
}
}
}
Next, say you have some class like:
public partial class MyClass
{
public string MyValue { get; set; }
}
And some XML containing an element that needs to be post-processed and converted into the current model, e.g. <OldValue>:
<MyClass><OldValue>Hello</OldValue></MyClass>
Then add a method to MyClass that:
Can be private or internal (in full trust) or public;
Has the same signature as XmlElementEventHandler;
Is marked with your custom attribute [XmlUnknownElementEventHandler];
Performs the necessary post-processing on the old element.
And now the unknown element will be forwarded to it when using a serializer constructed by XmlSerializationHelper.LoadFromXml().
E.g., your method might look like:
public partial class MyClass
{
[XmlUnknownElementEventHandler]
void HandleOldElement(object sender, XmlElementEventArgs e)
{
if (e.Element.Name == "OldValue")
{
Debug.WriteLine("{0}: processed property {1} with value {2}", this, e.Element.Name, e.Element.OuterXml);
MyValue = "Old value was: " + e.Element.InnerText;
}
}
}
And you would deserialize as follows:
var model = xmlString.LoadFromXml<MyClass>();
One advantage of this solution is that it doesn't modify the XSD generated for your types in any way.
Sample fiddle. (Note that, because the dotnetfiddle code executes in partial trust, the handlers must be public. That's not necessary in full trust.)
I am attempting to serialize just part of a class. I've added XML attributes to the class members so that the generated XML tags are correctly named to match a spec regardless of what my properties are named. This works fine when serializing the main class. However, if I just want to serialize part of the class, I lose the XML attributes and the names go back to their defaults. Is there a way to retain the XML attributes when serializing just part of a class?
[XmlRoot ("someConfiguration")]
public class SomeConfiguration
{
[XmlArray("bugs")]
[XmlArrayItem("bug")]
public List<string> Bugs { get; set; }
}
When I serialize the entire class, I get this (which is exactly as I would expect):
<someConfiguration>
<bugs>
<bug>Bug1</bug>
<bug>Bug2</bug>
<bug>Bug3</bug>
</bugs>
</someConfiguration>
If I attempt to just serialize the 'Bugs' part of the class, I get this (note the XML attributes that change the tag names are all ignored):
<ArrayOfString>
<string>Bug1</string>
<string>Bug2</string>
<string>Bug3</string>
</ArrayOfString>
I need to get this:
<bugs>
<bug>Bug1</bug>
<bug>Bug2</bug>
<bug>Bug3</bug>
</bugs>
How do I get the partial class to serialize with the above tags?
Or better yet, is there a way to specify tag names when serializing a simple List<object>. So that you can specify the tag used for the list instead of it using <ArrayOfobject> and specify the tag used for the array items instead of <object>?
is there a way to specify tag names when serializing a simple List.
In general, depending on the exact scenario, it may be possible to get this to work. See MSDN's How to: Specify an Alternate Element Name for an XML Stream. The example there involves overriding serialization of a specific field, but it may be possible to use the same technique to override whole type names as well.
But it seems like an awful lot of trouble to me. Instead, why not just handle the serialization explicitly:
private static string SerializeByLinqAndToString<T>(
List<T> data, string rootName, string elementName)
{
XDocument document = new XDocument(
new XElement(rootName, data.Select(s => new XElement(elementName, s))));
return SaveXmlToString(document);
}
private static string SaveXmlToString(XDocument document)
{
StringBuilder sb = new StringBuilder();
using (XmlWriter xmlWriter = XmlWriter.Create(sb,
new XmlWriterSettings { Indent = true, OmitXmlDeclaration = true }))
{
document.Save(xmlWriter);
}
return sb.ToString();
}
Call like this:
SomeConfiguration config = ...; // initialize as desired
string result = SerializeByLinq(config.Bugs, "bug", "bugs");
The above works only with a list of strings, or a list of types where the element content can be simply the result of calling ToString() on the instance of the type.
Using the full-blown serialization features in .NET might be worthwhile when dealing with complex types, but if all you've got is a simple list of strings, the LINQ-to-XML feature is very handy.
If you do have more complex types, you can transform each list element into an XElement for the DOM and serialize that:
private static string SerializeByLinq<T>(
List<T> data, string rootName, string elementName = null)
{
XDocument document = new XDocument(
new XElement(rootName, data.Select(t =>
ElementFromText(SerializeObject(t), elementName)
)));
return SaveXmlToString(document);
}
private static XElement ElementFromText(string xml, string name = null)
{
StringReader reader = new StringReader(xml);
XElement result = XElement.Load(reader);
if (!string.IsNullOrEmpty(name))
{
result.Name = name;
}
return result;
}
private static string SerializeObject<T>(T o)
{
XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
StringWriter textWriter = new StringWriter();
using (XmlWriter writer = XmlWriter.Create(textWriter,
new XmlWriterSettings { Indent = true, OmitXmlDeclaration = true }))
{
xmlSerializer.Serialize(writer, o,
new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty}));
}
return textWriter.ToString();
}
In this second example, you can omit the element name for the child, and it will just use whatever the type's set up to use already (e.g. the type name, or whatever [XmlRoot] is set to).
Just throwing this out there, you could wrap the List<> inside a custom class:
[XmlRoot("config")]
public class SomeConfiguration
{
[XmlElement("bugs")]
public BugList Bugs { get; set; }
[XmlElement("trees")]
public TreeList Trees { get; set; }
}
[XmlRoot("bugs")]
public class BugList
{
[XmlElement("bug")]
public List<string> Items = new List<string>();
}
[XmlRoot("trees")]
public class TreeList
{
[XmlElement("tree")]
public List<string> Items = new List<string>();
}
That will now allow you to serialize the individual Lists and they'll be rooted as you'd expect.
void Main()
{
var config = new SomeConfiguration
{
Bugs = new BugList { Items = { "Bug1", "Bug2" } },
Trees = new TreeList { Items = { "Tree1", "Tree2" } }
};
// Your config will work as normal.
Debug.WriteLine(ToXml(config)); // <config> <bugs>.. <trees>..</config>
// Your collections are now root-ed properly.
Debug.WriteLine(ToXml(config.Bugs)); // <bugs><bug>Bug1</bug><bug>Bug2</bug></bugs>
Debug.WriteLine(ToXml(config.Trees)); // <trees><tree>Tree1</tree><tree>Tree2</tree></trees>
}
public string ToXml<T>(T obj)
{
var ser = new XmlSerializer(typeof(T));
var emptyNs = new XmlSerializerNamespaces();
emptyNs.Add("","");
using (var stream = new MemoryStream())
{
ser.Serialize(stream, obj, emptyNs);
return Encoding.ASCII.GetString(stream.ToArray());
}
}
Found a 'work-around' way to do it.. Instead of putting XMLArray and XMLArrayList attributes above the List<>:
[XmlRoot ("someConfiguration")]
public class SomeConfiguration
{
[XmlArray("bugs")]
[XmlArrayItem("bug")]
public List<string> Bugs { get; set; }
}
Put an XmlElement attribute on the list which will specify the tag to be used for each element and not have a tag wrapping the list. Your class tag will in effect do that for you.
[XmlRoot ("bugs")]
public class SomeConfiguration
{
[XmlElement("bug")]
public List<string> Bugs { get; set; }
}
When you serialize the above, you will end up with:
<bugs>
<bug>Bug1</bug>
<bug>Bug2</bug>
<bug>Bug3</bug>
</bugs>
This question already has answers here:
How do I get json.net to serialize members of a class deriving from List<T>?
(3 answers)
Closed 6 years ago.
I can't find a way to serialize with JSON.NET a list of derived lists, and I'm starting to wonder if it's even possible. Let me explain the situation with some code.
I've created a new class which is derived from a list of a specific object (tried first with a generic one) and added a string property NomGroupe:
public class GroupeActes : List<Acte>
{
public string NomGroupe { get; set; }
public GroupeActes(string nom, List<Acte> liste)
{
NomGroupe = nom;
foreach (var acte in liste)
{
this.Add(acte);
}
}
}
Then, in my code, I've declared a list of this class (List<GroupeActes> listOfGroupeActes) and I fill it with data. For the serialization, I use this code:
JsonSerializer serializer = new JsonSerializer();
serializer.TypeNameHandling = TypeNameHandling.All;
using (StreamWriter sw = new StreamWriter(#"listOfGroupeActes.json"))
using (JsonWriter writer = new JsonTextWriter(sw))
{
serializer.Serialize(writer, listOfGroupeActes);
}
I've tried with and without the TypeNameHandling.All parameter and with several combination of Json.net properties and even with DataContract/DataMember.
So far, I only managed to get in my json file either the data of each nested List<Acte> without the NomGroupe property, or the other way around. But not both, which is what I'd like to have.
Two questions then:
Is it even possible?
If yes, how can I do it?
Thanks for your help!
You don't want to inherit from List<T>.
Create a list property instead:
public class GroupeActes
{
public List<Acte> Actes { get; set; }
public string NomGroupe { get; set; }
public GroupeActes(string nom, List<Acte> liste)
{
NomGroupe = nom;
Actes.AddRange(acte);
}
}
Lists (and other collection types) get special treatment while serializing. You don't want the collection type's public properties (such as Capacity and Count) in your output, so the property you added through inheritance won't be serialized either.
A collection is serialized like this:
if o is IEnumerable
foreach object s in o
serialize o
So the serializer won't even look at your enumerable's properties.
Try to use Newtonsoft Json.NET
string itemToSend = JsonConvert.SerializeObject(dataModel);