是否有与Delphi的Assign / AssignTo相同的.NET语法？

Question

Delphi has a standard mechanism where one object can be copied from another, paraphrased here as:

class Persistent 
{
    protected AssignError(Persistent source)
    {
       throw new ConvertError("Cannot assign a {0} to a {1}", source.GetType().Name, this.GetType().Name);
    }

    protected virtual AssignTo(Persistent destination)
    {
        destination.AssignError(this);
    }

    public virtual Assign(Persistent source)
    {
       source.AssignTo(this);
    }
}

Does the .NET FCL has a canonical syntax of copying objects between each other?

eg:

interface IPersistent
{
   public virtual Assign(Object source);
}

public class User : IPersistent
{
    private Image avatarThumbnail;
    private String name;

    public override Assign(Object source)
    {
       if (source is User)
       {
          this.avatarThumbnail = source.avatarThumbnail;
          this.name = source.Name;
       }
       else if (source is Image)
           avatarThumbnail = (Image)source;
       else if (source is DirectoryEntry)
           name = ((DirectoryEntry) source).Firstname + " " + ((DirectoryEntry) source).Lastname;
       else
           throw new AssignError("Assign from {0}", source.GetType());
    }
}

Yes i just invented a standard IPersistent interface; but is there already a mechanism to copy objects between each other?

Update

Note : i am talking about the opposite of cloning an object.

User originalUser = new User();
User theClone = originalUser.Clone();
theClone.Lastname = "Guyer";

originalUser.Assign(theClone);

Or, i don't even need to have a clone at all:

User u = new User();
u.Assign(salesOrder); //copy name/e-mail from the sales order

or

SalesOrder s = new SalesOrder();
s.SalesOrderDate = DateTime.Now;
User customer = new Customer("Kirsten");
s.Assign(user); //copy sold-to/ship-to information from the user

Answer 1

The .NET framework has the ICloneable interface:

Supports cloning, which creates a new instance of a class with the same value as an existing instance.

And:

The ICloneable interface contains one member, Clone , which is intended to support cloning beyond that supplied by MemberwiseClone . For more information about cloning, deep versus shallow copies, and examples, see the Object.MemberwiseClone method.

---

Update:

As far as I know, there is nothing equivalent to what you want (standard way to copy some values between different objects) in the BCL.

Answer 2

As an alternative to the standard ICloneable interface, you could perform the copy of public properties/fields using reflection. Here's some code written off the top of my head for doing so:

foreach(PropertyInfo mbr in src.GetType().GetProperties())
    mbr.SetValue(dst, src.GetValue(src, BindingFlags.GetProperty, null, null, null), BindingFlags.SetProperty, null, null, null)

foreach(FieldInfo mbr in src.GetType().GetFields())
    mbr.SetValue(dst, src.GetValue(src, BindingFlags.GetField, null, null, null), BindingFlags.SetField, null, null, null)