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Answer 1

A:

Most collection classes in .Net provide a constructor overload that allow you to pass in another collection like

dim copyOfBookMars as New List(of BookMark)(myOriginalBookMarkList)

Micah 2008-12-18 21:40:35

It is not a list it is a single Bookmark that I need a copy of that has a property that is a list of Bookmarks. Dim aBookmark As New FalconBookmark

2008-12-18 21:42:21

So i can't use this, I need a way to clone my Original Bookmark, or break the link to the orginal.

2008-12-18 21:52:32

Answer 2

A:

Been awhile with VB, but c# offers a clone() method.

steve_mtl 2008-12-18 21:55:57

The problem with Clone() is that the semantics are poorly defined - is it a shallow or a deep copy? Better approach is to use a copy constructor.

Bevan 2008-12-18 21:59:51

That same argument also applies to a copy constructor.Is the copy constructor a shallow copy or a deep copy?So, I wouldn't use that as a basis for your decision which way to go.Defining a method called clone() has some advantages over a copy constructor.A method can be polymorphic ...

Scott Wisniewski 2008-12-18 22:14:08

... This means that if you have a hierarchy of classes, that you can have an override of Clone in each class that can create something different.You can't do that with a copy constructor. Using "new Foo" always creates a Foo.If you don't need polymorphism, then it's really just about style ....

Scott Wisniewski 2008-12-18 22:16:15

... Do you like var copy = new Foo(original);orvar copy = original.Clone();

Scott Wisniewski 2008-12-18 22:17:09

I typically use var copy = original.Clone(), but now I am reconsidering and will be a little more selective.Great string of follow up comments!

steve_mtl 2008-12-24 04:02:45

Answer 3

A:

You don't generally make a copy of an Object, an Object makes a copy of itself (clone). Since an object contains state inforrmation, a bitwise copy can't be counted on as being appropriate; so the defining class needs to take care of it.

You may want to implement multiple simultaneous pointers (bookmarks) in your case.

le dorfier 2008-12-18 22:00:43

Answer 4

+2 A:

Create a new constructor for your bookmark class that takes an existing bookmark as the parameter.

Within this new constructor, copy all the property values from the existing bookmark onto the new one.

This technique is known as a "Copy Constructor".

There's an article on MSDN that goes into more detail - see How to Write a Copy Constructor.

Bevan 2008-12-18 22:05:35

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