c# - 克隆整个对象图

Question

使用此代码序列化对象时：

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);
    }
}

我注意到它不会复制关系。有没有办法做到这一点？

Answer 1

只需使用接受的构造函数重载preserveObjectReferences，并将其设置为 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; }
}

Answer 2

在 DatacontractSerializer 的构造函数中注释您的类[DataContract]或添加您的子类型。

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

Answer 3

要执行深度克隆，您可以考虑使用二进制序列化程序：

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);
    }
}

Answer 4

在序列化/反序列化步骤中，您需要一个二进制序列化程序来保留对象身份。