error with decimal in mvc3 - the value is not valid for field

Question

I'm following [Getting started with ASP.NET MVC 3][1]. And I can't add/edit with value of Price = 9.99 or 9,99. It said: "The value '9.99' is not valid for Price." and "The field Price must be a number."

How to fix this?

Model:

    public class Movie
{
    public int ID { get; set; }
    public string Title { get; set; }
    public DateTime ReleaseDate { get; set; }
    public string Genre { get; set; }
    public decimal Price { get; set; }
}

public class MovieDbContext : DbContext
{
    public DbSet Movies { get; set; }
}

Controller:

public class MovieController : Controller
{
    private MovieDbContext db = new MovieDbContext();

    //
    // GET: /Movie/

    public ViewResult Index()
    {
        var movie = from m in db.Movies
                     where m.ReleaseDate > new DateTime(1984, 6, 1)
                     select m;

        return View(movie.ToList()); 
    }

    //
    // GET: /Movie/Details/5

    public ViewResult Details(int id)
    {
        Movie movie = db.Movies.Find(id);
        return View(movie);
    }

    //
    // GET: /Movie/Create

    public ActionResult Create()
    {
        return View();
    } 

    //
    // POST: /Movie/Create

    [HttpPost]
    public ActionResult Create(Movie movie)
    {
        if (ModelState.IsValid)
        {
            db.Movies.Add(movie);
            db.SaveChanges();
            return RedirectToAction("Index");  
        }

        return View(movie);
    }

    //
    // GET: /Movie/Edit/5

    public ActionResult Edit(int id)
    {
        Movie movie = db.Movies.Find(id);
        return View(movie);
    }

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

    [HttpPost]
    public ActionResult Edit(Movie movie)
    {
        if (ModelState.IsValid)
        {
            db.Entry(movie).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        return View(movie);
    }

    //
    // GET: /Movie/Delete/5

    public ActionResult Delete(int id)
    {
        Movie movie = db.Movies.Find(id);
        return View(movie);
    }

    //
    // POST: /Movie/Delete/5

    [HttpPost, ActionName("Delete")]
    public ActionResult DeleteConfirmed(int id)
    {            
        Movie movie = db.Movies.Find(id);
        db.Movies.Remove(movie);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

    protected override void Dispose(bool disposing)
    {
        db.Dispose();
        base.Dispose(disposing);
    }
}
}

View:

    @model MvcMovies.Models.Movie

@{
ViewBag.Title = "Create";
}

Create




@using (Html.BeginForm()) {
@Html.ValidationSummary(true)

    Movie

    
        @Html.LabelFor(model => model.Title)
    
    
        @Html.EditorFor(model => model.Title)
        @Html.ValidationMessageFor(model => model.Title)
    

    
        @Html.LabelFor(model => model.ReleaseDate)
    
    
        @Html.EditorFor(model => model.ReleaseDate)
        @Html.ValidationMessageFor(model => model.ReleaseDate)
    

    
        @Html.LabelFor(model => model.Genre)
    
    
        @Html.EditorFor(model => model.Genre)
        @Html.ValidationMessageFor(model => model.Genre)
    

    
        @Html.LabelFor(model => model.Price)
    
    
        @Html.EditorFor(model => model.Price)
        @Html.ValidationMessageFor(model => model.Price)
    

    
        
    

}


@Html.ActionLink("Back to List", "Index")

public DbSet Movies { get; set; }
}

user_9446598 · Answer

In 2019, this problem is still not solved. Using ASP Core 2.1, my UI is in French (decimal separator= ',') and I couldn't get the validation to work anytime I had a decimal number.

I found a workaround, not ideal though: I created a french-based CultureInfo but I changed the decimal separator to be the same as in Invariant Culture : '.'.

This made the trick, my decimal numbers are now displayed US style (but I am ok with it) and validation works.

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });


        //Culture specific problems
        var cultureInfo = new CultureInfo("fr-FR");
        cultureInfo.NumberFormat.NumberDecimalSeparator = ".";
        System.Threading.Thread.CurrentThread.CurrentUICulture = cultureInfo;

    }

user_3762855 · Answer

This is an extension of Leniel Maccaferri solution that avoids problems related to the sending by the user-agent of decimal values in a different culture format from the server one. Its limits are bound to the thousands separator parsing that, when it is the only separator in the value, can raise wrong bindings.

/// 
/// custom decimal model binder
/// 
/// https://stackoverflow.com/users/114029/leniel-maccaferri
/// 
/// Integrated with a fix for the decimal separator issue.
/// This issue maybe depends from browsers interpretation of decimal values posted-back to the server when they receive response without any http content-language specific indication.
/// Important! decimal values caming from UI must not be formatted with thousands separator.
/// 
public class DecimalModelBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        ValueProviderResult valueResult = bindingContext.ValueProvider
            .GetValue(bindingContext.ModelName);

        ModelState modelState = new ModelState { Value = valueResult };

        object actualValue = null;

        if (valueResult.AttemptedValue != string.Empty)
        {
            try
            {
                var culture = Thread.CurrentThread.CurrentCulture;

                //This is needed to convert in the right manner decimal values coming from UI, as seems they always represent the decimal separator as a period("."). 
                //Maybe depends from browsers interpretation of decimal values posted-back to the server when they receive response without any http content-language specific indication.
                if (culture.NumberFormat.NumberDecimalSeparator == "," && valueResult.AttemptedValue.LastIndexOf(".") > 0)
                {
                    culture = new CultureInfo("en"); 
                }
                else if (Thread.CurrentThread.CurrentCulture.NumberFormat.NumberDecimalSeparator == "." && valueResult.AttemptedValue.LastIndexOf(",") > 0)
                {
                    culture = new CultureInfo("it");
                }

                actualValue = Convert.ToDecimal(valueResult.AttemptedValue, culture);

            }
            catch (FormatException e)
            {
                modelState.Errors.Add(e);
            }
        }

        bindingContext.ModelState.Add(bindingContext.ModelName, modelState);

        return actualValue;
    }
}

error with decimal in mvc3 - the value is not valid for field

10 Answers