Convert Anonymous Type to Class

Question

I got an anonymous type inside a List anBook:

var anBook=new []{

new {Code=10, Book ="Harry Potter"},
new {Code=11, Book="James Bond"}
};

Is to possible to convert it to a List with the following definition of clearBook:

public class ClearBook
{
  int Code;
  string Book; 
}

by using direct conversion, i.e., without looping through anBook?

Answer 1

Well, you could use:

var list = anBook.Select(x=> new ClearBook {
               Code = x.Code, Book = x.Book}).ToList();

but no, there is no direct conversion support. Oobviously you'll need to add accessors, etc (don't make the fields public) - I'd guess:

public int Code { get; set; }
public string Book { get; set; }

Of course, the other option is to start with the data how you want it:

var list =new List<ClearBook> {
    new ClearBook {Code=10, Book ="Harry Potter"},
    new ClearBook {Code=11, Book="James Bond"}
};

There are also things you could do to map the data with reflection (perhaps using an Expression to compile and cache the strategy), but it probably isn't worth it.

Answer 2

As Marc says, it can be done with reflection and expression trees... and as luck would have it, there's a class in MiscUtil which does exactly that. However, looking at your question more closely it sounds like you want to apply this conversion to a collection (array, list or whatever) without looping. That can't possibly work. You're converting from one type to another - it's not like you can use a reference to the anonymous type as if it's a reference to ClearBook.

To give an example of how the PropertyCopy class works though, you'd just need:

var books = anBook.Select(book => PropertyCopy<ClearBook>.CopyFrom(book))
                                 .ToList();