CODEWITHSUNDEEP
asp.net-mvchtml.dropdownlistfor
Helen Tekie
Helen Tekie

Reputation: 535

Dropdownlist value is null after posting to controller in ASP.NET MVC

I can get all Roles plus actually Role for chosed user, but then When I posting to EditUser action, then Dropdownlist sends null. I mean When the form posts to my controller, I get null from DropDownList.

Here is my Model

public class EditUserViewModel
    {
      public string Id { get; set; }
      public string Name { get; set; }
      public string Email { get; set; }
      public List<SelectListItem> ApplicationRoles { get; set; }
      public string ApplicationRoleId { get; set; }
    }

Here is Action

[HttpGet]
            public async Task<ActionResult> EditUser(string id)
            {
                EditUserViewModel model = new EditUserViewModel();
                model.ApplicationRoles = RoleManager.Roles.Select(r => new SelectListItem
                {
                    Text = r.Name,
                    Value = r.Id
                }).ToList();


                if (!String.IsNullOrEmpty(id))
                {
                    ApplicationUser user = await UserManager.FindByIdAsync(id);
                    if (user != null)
                    {
                        var role = await UserManager.GetRolesAsync(user.Id);
                        var existingRole = role.First();
                        string existingRoleId = RoleManager.Roles.Single(r => r.Name == existingRole).Id;
                        model.Id = user.Id;
                        model.FirstName = user.FirstName;
                        model.ApplicationRoleId = existingRoleId;
                        ViewBag.RoleId = new SelectList(RoleManager.Roles, "Id", "Name", model.ApplicationRoleId); 
                    }
                }
                return PartialView("_EditUser", model);
            }

And here is DropDownlist from _EditUser.cshtml

<div class="form-group">
                @Html.Label("Role typ", htmlAttributes: new { @class = "control-label col-md-6" })
                <div class="col-md-12" title="Ange antal datorer som finns i lager">
                    @Html.DropDownList("RoleId", null, new { @class = "form-control" })
                    @Html.ValidationMessageFor(model => model.ApplicationRoles, "", new { @class = "text-danger" })
                </div>
            </div>

Getting null Only from DropDownList, not from @Html.EditorFor /Thanks in advance!

Upvotes: 0

Views: 2403

Answers (2)

user3559349
user3559349

Reputation:

Forms post back the name/value pairs of their successful form controls. Your generating a <select> element with name="RoleId" but you model does not contain a property named RoleId. Since you want to bind the selected option to the ApplicationRoleId role property, then you view needs to be

@Html.LabelFor(m => m.ApplicationRoleId)
@Html.DropDownListFor(m => m.ApplicationRoleId, Model.ApplicationRoles)
@Html.ValidationMessageFor(m => m.ApplicationRoleId)

Notes:

  1. Your current @Html.Label(..) code does not create a label associated with your dropdownlist (clicking on it will not set focus)
  2. The ValidationMessageFor() need to be applied to the property your binding to, not the SelectList
  3. Delete you ViewBag.RoleId = new SelectList(..) code. Your have already assigned the selectlist to the ApplicationRoles property (and you should never need ViewBag if have a view model anyway)

Upvotes: 1

Augusto
Augusto

Reputation: 89

Because you are declare that only HttpGet methods are allow in that method of the controller. Thats why

Upvotes: 0

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