Value cannot be null. Parameter name: items (in Dropdown List) ASP.NET MVC5

Question

I have problem in my code. I\'m using the registration form which comes with MVC5 , I added a field \"Role\" as a Dropdownlist to assign a role to the user while creating a

Answer 1

The solution that worked for me in MVC5 for editing an existing user

Model (part of)

public IEnumerable Roles { get; set; }

View

@Html.DropDownListFor(model => model.UserRole, new SelectList(Model.Roles, Model.UserRole), new { @class = "form-control" })

Controller (Get)

 var model = new EditUserViewModel()
        {
            UserName = user.UserName,
            Email = user.Email,
            IsEnabled = user.IsEnabled,
            Id = user.Id,
            PhoneNumber = user.PhoneNumber,
            UserRole = userRoleName,

            // a list of all roles
            Roles = from r in RoleManager.Roles orderby r.Name select r.Name
        };