Question

I’m using this approach using viewmodel for manipulating values inside combo boxes. Now, I’m struggle to select as default value actual selected value used in create action, not the first one from combo. I know this is fourth parameter in SelectList but I do not know how to use actual UserGroupId cause it’s give me an error when using like these

var model = new UserViewModel 
    { 
        UserGroups = new SelectList(GetAllUsers(), "UserId", "Name", UserGroupId) 
    } 
    return View(model); 

---

 public class UserViewModel 
    { 
        public int UserGroupId { get; set; } 
        public IEnumerable<SelectListItem> UserGroups { get; set; } 
    } 

Answer 1

Like this:

var model = new UserViewModel 
{ 
    // preselct an item in the dropdown whose value equals 5
    // This means that inside your `GetAllUsers()` collection you must
    // have an element with UserId=5 and this element will automatically be
    // preselcted. Here you could put any value of course
    UserGroupId = 5,
    UserGroups = new SelectList(GetAllUsers(), "UserId", "Name") 
};
return View(model);

and in your view:

@model UserViewModel
...
@Html.DropDownListFor(x => x.UserGroupId, Model.UserGroups)