从该对象中分配一个对象C＃

Question

I was curious to know if there was an easy way to do the following.

public class Person
{
    public String Name{ get; set; }

    public void Load(Stream stream)
    {
        this = new XmlSerializer(GetType()).Deserialize(stream) as Person;
    }

    public void Save(Stream stream)
    {
        new XmlSerializer(GetType()).Serialize(stream, this);
    }
}

I realize that this will not compile; however, I find that sometimes I wish to assign an object from within itself. (ie the object undergoes a massive change and I wish to instead of changing each value, simply "reset" the object by calling its constructor and setting the object to its new version).

Any thoughts on how to do this?

Answer 1

You could do this with Automapper that would just copy the contents of an instance into your instance:

public void Load(Stream stream)
{
    Mapper.DynamicMap( new XmlSerializer(GetType()).Deserialize(stream) as Person, this );
}

Nevertheless, I would prefer

public static Person Load(Stream stream)
{
    return new XmlSerializer(GetType()).Deserialize(stream) as Person;
}

so that instead of overwriting the contents, you return a new instance and could just switch references in the client code.

Answer 2

Just use a static method that returns a new instance:

public class Person
{
    public String Name { get; set; }

    public static Person Load(Stream stream)
    {
        return new XmlSerializer(GetType()).Deserialize(stream) as Person;
    }
}

Call it like this:

var person = Person.Load(someStream);

Edit: I didn't notice your requirement that this is in an interface implementation. If possible, you may want to refactor the design. If you can't and your object is simple enough, you could instantiate a new object and copy the members over:

public void Load(Stream stream)
{
    Person p = new XmlSerializer(GetType()).Deserialize(stream) as Person;
    // todo: copy properties from p to this:
    // this.Name = p.Name;
    // etc
}