CODEWITHSUNDEEP
c#serializationdatacontractobject-graph
xplat
xplat

Reputation: 8626

Clone Whole Object Graph

While using this code to serialize an object:

public object Clone()
{
    var serializer = new DataContractSerializer(GetType());
    using (var ms = new System.IO.MemoryStream())
    {
        serializer.WriteObject(ms, this);
        ms.Position = 0;
        return serializer.ReadObject(ms);
    }
}

I have noticed that it doesn't copy the relationships. Is there any way to make this happen?

Upvotes: 6

Views: 5523

Answers (4)

Marc Gravell
Marc Gravell

Reputation: 1062530

Simply use the constructor overload that accepts preserveObjectReferences, and set it to true:

using System;
using System.Runtime.Serialization;

static class Program
{
    public static T Clone<T>(T obj) where T : class
    {
        var serializer = new DataContractSerializer(typeof(T), null, int.MaxValue, false, true, null);
        using (var ms = new System.IO.MemoryStream())
        {
            serializer.WriteObject(ms, obj);
            ms.Position = 0;
            return (T)serializer.ReadObject(ms);
        }
    }
    static void Main()
    {
        Foo foo = new Foo();
        Bar bar = new Bar();
        foo.Bar = bar;
        bar.Foo = foo; // nice cyclic graph

        Foo clone = Clone(foo);
        Console.WriteLine(foo != clone); //true - new object
        Console.WriteLine(clone.Bar.Foo == clone); // true; copied graph

    }
}
[DataContract]
class Foo
{
    [DataMember]
    public Bar Bar { get; set; }
}
[DataContract]
class Bar
{
    [DataMember]
    public Foo Foo { get; set; }
}

Upvotes: 16

Darin Dimitrov
Darin Dimitrov

Reputation: 1038710

To perform a deep clone you might consider using a binary serializer:

public static object CloneObject(object obj)
{
    using (var memStream = new MemoryStream())
    {
        var binaryFormatter = new BinaryFormatter(
             null, 
             new StreamingContext(StreamingContextStates.Clone));
        binaryFormatter.Serialize(memStream, obj);
        memStream.Seek(0, SeekOrigin.Begin);
        return binaryFormatter.Deserialize(memStream);
    }
}

Upvotes: 1

Seb
Seb

Reputation: 2715

You need a binary serializer to preserve objects identity during the serialization/deserialization step.

Upvotes: 0

Mikael Svenson
Mikael Svenson

Reputation: 39697

Either annotate your classes with [DataContract] or add your child types in the constructor of DatacontractSerializer.

var knownTypes = new List<Type> {typeof(Class1), typeof(Class2), ..etc..};
var serializer = new DataContractSerializer(GetType(), knownTypes);

Upvotes: 1

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