DropDownListFor did not automatically selected property

Question

In controller, I am creating ViewModel and filling its properties:

[HttpGet]
public ActionResult Index()
{
    PermissionViewModel vm = new PermissionViewModel()
    {
        Users = new List<UserViewModel>()
        {
            new UserViewModel()
            {
                Id = 1,
                Email = "foo.bar@example.com",
                IsSelected = false,
                Permissions = new List<SelectListItem>()
                {
                    new SelectListItem() { Value = "1", Text="Admin" },
                    new SelectListItem() { Value = "2", Text="Customer" },
                    new SelectListItem() { Value = "3", Text="Employeer" }
                },
                SelectedPermissionId = 2,
            }
        },

        Pagination = new List<SelectListItem>() {
            new SelectListItem() { Value = "10", Text = "10" },
            new SelectListItem() { Value = "20", Text = "20"}
        },
    };

    return View(vm);
}

Now, I want to display data. I am having problem with Permissions. I set SelectedPermissionId to 2, so I expected, that Customer will be automatically selected.

@foreach (var user in Model.Users)
{
    <tr>
        <td>@user.Email</td>
        <td>
            @Html.DropDownListFor(x => user.SelectedPermissionId, user.Permissions)
        </td>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id = user.Id }) | @Html.ActionLink("Delete", "Delete", new { id = user.Id })
        </td>
        <td>@Html.CheckBoxFor(x => user.IsSelected)</td>
    </tr>
}

Unfortunelly Admin is selected. Why does that happen?

Edit

I found out that If I Move Permissions and SelectedPermissionId to PermissionViewModel then this:

@Html.DropDownListFor(x => x.SelectedPermissionId, Model.Permissions)

Is working. Now Customer is selected. But I have to have this in UserViewModel..

Solution

I found solution. I had to change from this:

@Html.DropDownListFor(x => user.SelectedPermissionId, user.Permissions)

To this:

@Html.DropDownListFor(x => user.SelectedPermissionId, new SelectList(user.Permissions, "Value", "Text", user.SelectedPermissionId))

Does anyone know why that was necessary?

score -1 · Answer 1 · answered Jun 26 '18 at 09:59

your solution is good usually I was using this code in dropdownlist I think it is easier than using helper

<select style="height:auto" class="form-control " id="Permissions" name="Permissions" value="@permission">
                 <!--   <option value="null"
                            @if (permission.Text == null) { <text> selected</text>    }>
                    Permissions
                    </option>
 -->
                    @for (int i = 0; i < ViewBag.Permissions.Count; i++)

                    {
                      <option value="@ViewBag.Permissions[i].Text "
                              @if (permission.Text == ViewBag.Permissions[i].Text ) { <text> selected</text>}>
                        @ViewBag.Permissions[i].Text 
                      </option>
                    }
                  </select>

DropDownListFor did not automatically selected property

Edit

Solution

1 Answers1