DataContractSerializer Class

Serializes and deserializes an instance of a type into an XML stream or document using a supplied data contract. The DataContractSerializer provides a flexible, high-performance way to transform objects to XML and back, supporting complex types, collections, and inheritance.

Syntax

public class DataContractSerializer : XmlObjectSerializer
{
    public DataContractSerializer(Type type);
    public DataContractSerializer(Type type, IEnumerable<Type> knownTypes);
    public DataContractSerializer(Type type, string rootName, string rootNamespace);
    public DataContractSerializer(Type type, IEnumerable<Type> knownTypes, int maxItemsInObjectGraph, bool ignoreExtensionDataObject, bool preserveObjectReferences, IDataContractSurrogate dataContractSurrogate);
    // … properties and methods …
}

Remarks

The serializer works based on data contracts—explicit declarations of how a type's data is represented in XML. When no data contract is defined, the serializer infers one from the public members of the type.

Supports preserveObjectReferences to handle circular references.
Allows custom IDataContractSurrogate implementations for advanced scenarios.
Optimized for performance; frequently used in WCF services.

Examples

Serialize an object to a file and then deserialize it back.

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Xml;

[DataContract]
public class Person
{
    [DataMember] public string FirstName { get; set; }
    [DataMember] public string LastName { get; set; }
    [DataMember] public int Age { get; set; }
}

class Program
{
    static void Main()
    {
        var person = new Person { FirstName = "Ada", LastName = "Lovelace", Age = 36 };
        var serializer = new DataContractSerializer(typeof(Person));

        // Serialize
        using (var stream = new FileStream("person.xml", FileMode.Create))
        using (var writer = XmlDictionaryWriter.CreateTextWriter(stream, System.Text.Encoding.UTF8))
        {
            serializer.WriteObject(writer, person);
        }

        // Deserialize
        Person deserialized;
        using (var stream = new FileStream("person.xml", FileMode.Open))
        using (var reader = XmlDictionaryReader.CreateTextReader(stream, XmlDictionaryReaderQuotas.Max))
        {
            deserialized = (Person)serializer.ReadObject(reader);
        }

        Console.WriteLine($\"{deserialized.FirstName} {deserialized.LastName}, Age {deserialized.Age}\");
    }
}

Properties

KnownTypes – Gets the collection of types that may be present in the object graph.
PreserveObjectReferences – Indicates whether object reference preservation is enabled.
DataContractSurrogate – Gets the surrogate used during serialization.

Methods

WriteObject(XmlWriter, Object) – Serializes the supplied object.
ReadObject(XmlReader) – Deserializes the XML content into an object.
IsStartObject(XmlReader) – Determines whether the reader is positioned at the start of a serialized object.