How to deep copy a class without marking it as Serializable

c#, cloning, deep-copy

Solution

I stopped using serialization for deep copying anyway, because there is not enough control (not every class needs to be copied the same way). Then I started to implement my own deep copy interfaces and copy every property in the way it should be copied.

Typical ways to copy a referenced type:

- use copy constructor

- use factory method (eg. immutable types)

- use your own "Clone"

- copy only reference (eg. other Root-Type)

- create new instance and copy properties (eg. types not written by yourself lacking a copy constructor)

Example:

class A
{
  // copy constructor
  public A(A copy) {}
}

// a referenced class implementing 
class B : IDeepCopy
{
  object Copy() { return new B(); }
}

class C : IDeepCopy
{
  A A;
  B B;
  object Copy()
  {
    C copy = new C();

    // copy property by property in a appropriate way
    copy.A = new A(this.A);
    copy.B = this.B.Copy();
  }
}

You may think that this a huge amount of work. But at the end, it is easy and straight forward, can be tuned where needed and does exactly what you need.

Problem

Given the following class: ``` class A { public List<B> ListB; // etc... } ``` where `B` is another class that may inherit/contain some other classes. Given this scenario: - `A` is a large class and contains many reference types - I cannot mark `B` as `[Serializable]` as I don't have access to source code of `B` The following methods to perform deep copying do not work: - I cannot use `ICloneable` or `MemberwiseClone` as class `A` contains many reference types - I cannot write a copy constructor for `A`, as the class is large and continuously being added to, and contains classes (like `B`) that cannot be deep copied - I cannot use serialization as I cannot mark a contained class (like `B`, where no source code available) as `[Serializable]` How can I deep copy class `A`?

Original source

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