MVC 2 ApplyOriginalValues

Montero · May 18th, 2013, 02:46 PM

Hello everyone, this is my first post on the forum.

I'm learning MVC 2 with the Wrox Visual Studio 2010 and .Net 4 (six in one) book.

I'm a bit confused when i have to use "ApplyOriginalValues".

I've detach, then a new attach and finally ApplyOriginalValues.

C# Code from the Wrox book

Code:

context.Books.ApplyOriginalValues(
new Book { Id = editedBook.Id });

The code is working. But the question is: Why a New entity needs to be created?

My vb code is :

Code:

                    context.Books.Attach(editedBook)
                    Dim newBook As New Book
                    newBook .Id = editedBook.Id
                    context.Books.ApplyOriginalValues(newBook)
                    context.SaveChanges()

Thanks a lot for your help.