How can use MVC DropDownlist

Question

I have a problem with DropDownlist in MVC I use ModelView in my application and this is my code

namespace MedicallexiconProject.ViewModel
{
    public class WordViewModel
    {
        private readonly ICategoryService _categoryService;
        public WordViewModel(ICategoryService categoryService)
        {
            _categoryService = categoryService;
            var selectList = _categoryService.GetAllCategorysSelectList().
                Select(x => new SelectListItem
                {
                    Text = x.Name,
                    Value = x.ID.ToString()
                }).ToList();
            Categories = selectList;
        }

        public WordViewModel()
        {

        }
        public string Name { get; set; }
        private IList<SelectListItem> _categories;
        public IList<SelectListItem> Categories
        {
            get
            {
                if (_categories == null)
                {
                    _categories = new List<SelectListItem>();
                }
                return (_categories);
            }

            set { _categories = value; }
        }
    }
}

and this is my controller

[HttpGet]
public ActionResult Create()
{
    var wordViewModel = new WordViewModel(_categoryService);
    ViewBag.CategoryID = wordViewModel.Categories;
    return View();
}

[HttpPost]
public ActionResult Create(WordViewModel wordViewModel)
{
    Mapper.CreateMap<WordViewModel, Word>();

    var word = new Word();
    Mapper.Map(wordViewModel, word);

    if (ModelState.IsValid)
    {
        _wordService.AddNewWord(word);
        _uow.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(wordViewModel);
}

Now how can I insert dropdownlist in my View?

You should not put logic in your ViewModel, logic that fills your ViewModel should go in your controller action. The ViewModel should be a dumb class with no business logic or data access logic. — CD Smith
– CD Smith, Commented Jun 17, 2012 at 16:34

Shyju · Accepted Answer · 2012-06-17 18:22:59Z

3

As AlfalfaStrange mentioned, you should not add logic in your ViewModel. That makes it ugly ! Keep your ViewModel simple POCO.

Add one more property in your ViewModel called "SelectedCategoryID" like this

public class WordViewModel
{
  public int SelectedCategoryID { set;get;}
  public IList<SelectListItem> Categories { set;get;}
  public string Name { set;get;}
}

Initialize your Items (Categories) of your ViewModel in your GET method. Here i am calling a method called GetCategories which returns a list of categories.I can simply call the method wherever i want.

public ActionResult Create()
{
   var model=new WordViewModel();
   model.Categories=YourService.GetCategories();
   return View(model);
}

In your strongly typed Create view , use this

@model WordViewModel
using(@Html.BeginForm())
{

  @Html.DropDownFor(x=>x.SelectedCategoryID,
               new SelectList(Model.Categories,"Value","Text"),"Select Category")
  <input type="submit" value="Save" />
}

In your HttpPost action method , you can check for wordViewModel.SelectedCategoryID for the selected value.

[HttpPost]
public ActionResult Create(WordViewModel wordViewModel)
{
   if(ModelState.IsValid)
   {
     //Checck for wordViewModel.SelectedCategoryID here now
   }
   //some validation failed. Let's reload the category data again.
   wordViewModel.Categories=YourService.GetCategories();
   return View(wordViewModel);
}

edited Jun 17, 2012 at 18:22

answered Jun 17, 2012 at 16:36

Shyju

220k106 gold badges421 silver badges499 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Mohammad Over a year ago

Hello.can i retun from view a Category Object to mapping?

Shyju Over a year ago

@MohammadJafari mapping means ?

Mohammad Over a year ago

var category = _categoryService.GetByID(wordViewModel.SelectedCategoryID); word.Category = category;

Mohammad Over a year ago

var category = _categoryService.GetByID(wordViewModel.SelectedCategoryID); word.Category = category;

kman · Accepted Answer · 2014-05-20 19:14:25Z

0

It's absolutely fine to include code that loads a dropdown list in your view model. A select list and a drop down are both "view" items.... they are not related to business logic and your controller and model need not know anything about SelectLists or SelectListItems or DropDownList, etc.

answered May 20, 2014 at 19:14

kman

1

1 Comment

secretformula Over a year ago

Please elaborate why :0. This post is a year old you must have something to add so please add all you know :)

Collectives™ on Stack Overflow

How can use MVC DropDownlist

2 Answers 2

4 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related