ASP.NET MVC 5 : System.ArgumentNullException on DropDownList

Question

Hello everyone, well i'm facing a problem here, i've created an asp.net mvc5 web application and in it i've used a DropDownList , when i trie to create a new module

i receive this exception:'System.ArgumentNullException' occurred in System.Web.Mvc.dll but was not handled in user code

Additional information: Value cannot be null.

 

This is my controller:

 

// GET: Module/Create

public ActionResult Create()

{

List ListAppli = new List()

{

new SelectListItem() {Text="Tablette", Value="Tablette"},

new SelectListItem() {Text="Mobile", Value="Mobile"},

};

ViewBag.ListAppli = ListAppli;

return View();

}

// POST: Module/Create

[HttpPost]

public ActionResult Create(Module module)

{

if (ModelState.IsValid)

{

db.Modules.Add(module);

db.SaveChanges();

var idManager = new IdentityManager();

var success = idManager.CreateRole(module.libelle+" : "+module.application);

return RedirectToAction("Index");

}

return View(module);

}

//And this is my DropDownList 

 

Application

@Html.DropDownListFor(model => model.application, new SelectList(ViewBag.ListAppli, "Value", "Text"))

//And this is the model 

 

namespace AspNetRoleBasedSecurity.Models

{

public class Module

{

[Key]

public int id { get; set; }

[Required(ErrorMessage = "Le code est requis!")]

[Display(Name = "Code")]

public string code { get; set; }

[Required(ErrorMessage = "Le libellé est requis!")]

[Display(Name = "Libelle")]

public string libelle { get; set; }

[Display(Name = "Application")]

public string application { get; set; }

}

}

//Any idea please :D and thnx ^^