Question

I’m building a game and there is basic inheritance hiearchy:

GameObject is a base class, has a virtual method called Clone

PlatformObject is derived from GameObject, overriding the Clone method

I have a serializer/deserializer generic class for any GameObject or derivations defined as below:

public class XmlContentReaderBase<T> where T : GameObject

My XML Reader class is unaware of my derived type. I’ve got a problem with this line:

        T obj = serializer.Deserialize(input) as T;
        return obj.Clone() as T;

The first line runs fine, and returns a PlatformObject which is correct. But the second line calls the Clone method of the base class, GameObject, which is not what I want. I need to call PlatformObject.Clone method, how can I get this done?

Thanks,
Can.

Answer 1

I wrote an implementation very close to this and see Clone referencing the derived object’s Clone method (cheated a bit by creating a new object rather than deserializing one).

Post more code?

using System.Text;

namespace GenericExperiment
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlContentReaderBase<PlatformObject>.Deserialize();
            Console.ReadKey();
        }
    }

    class GameObject : ICloneable
    {
        object ICloneable.Clone()
        {
            Console.WriteLine("I am the base class");
            return null;
        }
    }

    class PlatformObject: GameObject, ICloneable
    {
        object ICloneable.Clone()
        {
            Console.WriteLine("I am the derived class");
            return null;
        }
    }

    class XmlContentReaderBase<T> where T : GameObject, new()
    {
        static public object Deserialize()
        {
            T obj = new T();
            ((ICloneable)obj).Clone();
            return obj;
        }
    }

}

Output:

I am the derived class