public ActionResult ViewDataWay(int id)
{
 Book book =bookRepository.GetBook(id);
 ViewData["Countries"] = new SelectList(PhoneValidator.Countries, book.Country);
 return View(book);
}

<div class="editor-field">
    <%= Html.DropDownList("Country", ViewData["Countries"] as SelectList) %>
    <%: Html.ValidationMessageFor(model => model.Country) %>
</div>

[HttpPost]
public ActionResult ViewDataWay(int id, FormCollection collection)
{
  Book book = bookRepository.GetBook(id);
  UpdateModel<Book>(book);
  bookRepository.Save(book);
  return RedirectToAction("Details", new { id=id});
}

public class BookViewModel 
{ 
 public Book Book 
 { 
   get; 
   set; 
 } 
 public SelectList Countries
 {
   get;
   set;
 }
 public BookViewModel(Book book)
 {
   Book = book;
  Countries = new SelectList(PhoneValidator.Countries,book.Country);
 }
}

public ActionResult ViewModelWay(int id)
{
  Book book = bookRepository.GetBook(id);
  return View(new BookViewModel(book));
}

public ActionResult TempDataWay(int id)
{
   Book book = bookRepository.GetBook(id);
   TempData["Countries"] = new SelectList(PhoneValidator.Countries, book.Country);
   return View(book);
}

<div class="editor-field">
  <%= Html.DropDownList("Country", TempData["Countries"] as SelectList) %>
  <%: Html.ValidationMessageFor(model => model.Country) %>
</div>

public ActionResult Test1() 
{ 
  TempData["text"] = "1-2-3"; 
   ViewData["text"] = "1-2-3"; 
   return RedirectToAction("Test2"); 
}
public ActionResult Test2()
{
   string text1 = TempData["text"] as string;
  string text2 = ViewData["text"] as string;
   return View();
}