Conditional validation on model in MVC

Question

I have a view & model that I use for both the edit and the insert page for a record. One of the business requirements is that a certain field is required on edit but not

Answer 1

You can try on validation with:

ModelState.Remove("ProposedCost");

Or extending your model like this:

public class NewModeViewModel : EditModeViewModel
{
   public new decimal ProposedCost { get; set; }
}

and passing to the edit view.