如何在MVC中使用单独的模型类进行验证

Question

I am not sure on how to implement this, I have a MovieController.cs in the Controllers folder and a MovieCreateViewModel.cs in the Models folder. I need to add validation for the create, edit and delete views.

MovieDetailsViewModel.cs

public class MovieDetailsViewModel
{
    public int Id { get; set; }
 }     

then I have MovieController.cs

public class MovieController : Controller
{

    Connect connection;
    MovieCreateViewModel movie;
    MovieDetailsViewModel id;

    public MovieController()
    {
        this.connection = new Connect();
        this.movie = new MovieCreateViewModel();
        this.id = new MovieDetailsViewMode();
    } 

    public ActionResult Edit(MovieDetailsViewModel id)
    {
        movie = this.connection.MovieContext.Where(m => m.ID == id).SingleOrDefault();  **//I get an error here**
        return View(movie);
    }

    //
    // POST: /Movie/Edit/5

    [HttpPost]
    public ActionResult Edit(MovieCreateViewModel movieedit)
    {
        try
        {
            if (ModelState.IsValid)
            {
                this.connection.MovieContext.AddObject(movieedit);
                this.connection.MovieContext.Context.SaveChanges();
                return RedirectToAction("Index");
            }

        }
        catch
        {
            return View(movieedit);
        }
    }

for the httpPost I made the type MovieDetailsViewModel id in the parameter list Where do I go from here please?

Thanks

Answer 1

Validation will now be performed on your model instance, to check it, you do:

ModelState.IsValid

In the controller method prior to the save operation. As long as the input names on the view correspond with your model class's property names, binding and validation will be performed implicitly prior to your action method being executed. To show your validation messages in your view, add a Html.ValidationMessage() to the top of the view. Hope this helps. By the way its well worth checking out Foolproof Validation which provides conditional validation attributes and some other good stuff.

Answer 2

Better practice would be use seperate model and viewmodel. Convert your model to viewmodel and then pass it to view

public ActionResult Edit(int id)
{
     var movie = this.connection.MovieContext.SingleOrDefault(m => m.ID == id);
     var vm = new MovieCreateViewModel{ Id = movie.Id};
     return View(vm);
}

//
// POST: /Movie/Edit/5

[HttpPost]
public ActionResult Edit(MovieCreateViewModel vm)
{
    try
    {
        if (ModelState.IsValid)
        {
            var movie = new Movie{Id = vm.Id};
            this.connection.MovieContext.Attach(movie);
            this.connection.MovieContext.Context.SaveChanges();
            return RedirectToAction("Index");
        }

    }
    catch
    {
        return View(movieedit);
    }
}