public class Book

{

        [Key]

        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]

        public int Id { get; set; }

        [Required, MaxLength()]

        public string Title { get; set; }

        public Double? Price { get; set; }

}

var bkList = db.Books.Select(allBooks => new { Id = allBooks.Id, Title = allBooks.Title }).Select(b => new Book { Id=b.Id,Title=b.Title});

var bkList2 = db.Books.Select(allBooks => new { Id = allBooks.Id, Title = allBooks.Title }).ToList().ConvertAll<Book>(b => new Book(){ Id=b.Id,Title=b.Title});

//声明一个与Book一模一样的克隆类

public class BookClone

{

    public int Id { get; set; }

    public string Title { get; set; }

    public Double Price { get; set; }

}

var bkList3 = db.Books.Select(allBooks => new BookClone { Id = allBooks.Id, Title = allBooks.Title });