MVC3 C# ViewModel on Postback for saving

I have this certain viewmodel with viewmodels and collections. When I click save button that invokes postback, I can't get the viewmodels and collections inside the viewmodel. I need to declare 开发者_开发知识库viewmodels and collections in the parameter of the function in able to get it. Is there a way to get the viewmodel complete with it's viewmodels and collections?

I have this Customer viewModel

public class CustomerViewModel 
{ 
   public int Id { get; set; } 
   public string Name { get; set; } 
   public PersonInfoViewModel PersonInfoViewModel { get; set; } 
   public ICollection<PurchasesViewModel> PurchasesViewModel { get; set; } 
} 

when I try to postback in my controller:

[HttpPost] 
public ActionResult New(FormCollection collection, CustomerViewModel customerViewModel, PersonInfoViewModel personInfoViewModel, ICollection<PurchasesViewModel> purchasesViewModel) 
{ 
   customerViewModel.PersonInfoViewModel = personInfoViewModel; 
   ... 
}

I forgot to mention that the ViewModels and Collections are rendered using partial views. Thanks

---

You can't use RenderPertial for the rendering of a ViewModel in Viewmodel.

You have to use @Html.EditorFor(model => model.PurchasesViewModel)

Then make a folder named EditorTemplates, either in the shared folder or in the folder you're surfing.

Next you have to create a view in that folder with the ViewModels name. So in your situation you have to make a view called PurchasesViewModel