Help understanding the basics of AutoMapper - asp.net

Question

So I have this two classes:
public class PhysicalTest
{
public int ID { get; set; }
public DateTime CreationDate { get; set; }
public int Weight { get; set; }
public int Height { get; set; }
public int Systolic { get; set; }
public int Diastolic { get; set; }
public int Pulse { get; set; }
}
public class PhysicalTestFormViewModel
{
public int ID { get; set; }
public DateTime CreationDate { get; set; }
[Required]
public int Weight { get; set; }
[Required]
public int Height { get; set; }
public int Systolic { get; set; }
public int Diastolic { get; set; }
public int Pulse { get; set; }
}
This is my AutoMapper configuration
Mapper.CreateMap<PhysicalTestFormViewModel, PhysicalTest>();
When I do this it works just fine
[HttpPost]
public ActionResult Create(int ehrId, PhysicalTestFormViewModel physicaltestvm)
{
EHR ehr = ehrRepository.Find(ehrId);
if (ehr.UserName != User.Identity.Name)
return View("Invalid Owner");
if (ModelState.IsValid)
{
PhysicalTest physicalTest= new PhysicalTest();
Mapper.Map(physicaltestvm, physicalTest);
physicalTest.PerformedBy = "Yo";
physicalTest.CreationDate = DateTime.Now;
ehr.PhysicalTests.Add(physicalTest);
ehrRepository.Save();
return RedirectToAction("Index");
}
else
{
return View(physicaltestvm);
}
}
But when I do this I get an error
Trying to map Summumnet.PhysicalTest
to
Summumnet.ViewModels.PhysicalTestFormViewModel.
Missing type map configuration or
unsupported mapping. Exception of type
'AutoMapper.AutoMapperMappingException'
was thrown.
public ActionResult Edit(int ehrId, int id)
{
EHR ehr = ehrRepository.Find(ehrId);
if (ehr.UserName != User.Identity.Name)
return View("Invalid Owner");
var physicalTest = ehr.PhysicalTests.Where(test => test.ID == id).Single();
PhysicalTestFormViewModel physicaltestvm = new PhysicalTestFormViewModel();
Mapper.Map(physicalTest, physicaltestvm);
return View(physicaltestvm);
}
In the scenario where the error is thrown I simply want to construct an ViewModel to display an Edit form.... what is the standard way of doing this?

Answer 1

You have only defined a mapping from PhysicalTestFormViewModel to PhysicalTest:
Mapper.CreateMap<PhysicalTestFormViewModel, PhysicalTest>();
You also need the opposite one:
Mapper.CreateMap<PhysicalTest, PhysicalTestFormViewModel>();
See this related SO question and answers.

Answer 2

you may do dynamic mapping where you dont have to create any maps
public ActionResult (PhysicalTestFormViewModel ptvm)
{
//other to wrote codes
EHR ehr = ehrRepository.Find(ehrId);
AutoMapper.Mapper.DynamicMap<PhysicalTestFormViewModel, PhysicalTest>(ptvm, ehr);
db.SaveChanges();
}