Difficulties with DropDownlist in ASP.Net MVC5

Question

I'm struggling with dropdownlist tried several methods online and all failed will show the methods that I tried.

Objective Create a Reciept with date,reference... & country. Country is Required and should be a dropdownlist.

So the Table for Reciept("ID, Name, Date, Address, City, CountryList).

RecieptModel

public class TransactionModel
{
    public int ID { get; set; }
    public int Name{ get; set; }
    public DateTime Date { get; set; }
    public string Address { get; set;}
    public string City { get; set; }
    public CountryList CountryList { get; set; }
}

public class ApplicationDbContext : DbContext
{
    public DbSet<RecieptModel> Reciepts { get; set;}
    public DbSet<CountryList> coutryList { get; set; }
}

CountryList

public class CountryList
{
    public byte Id { get; set; }

    public enum Country
    {
        Germany,
        US,
        UK
    }
}

Controller

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "ID,Name,Date,City,CountryList")] Reciepts reciepts)
{
    if (ModelState.IsValid)
    {
        db.Reciepts.Add(reciepts);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

    return View(reciepts);
}

View

<div class="form-group">
    @Html.LabelFor(model => model.CountryList, new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EnumDropDownListFor(model => model.CountryList)
        @Html.ValidationMessageFor(model => model.CountryList)
    </div>
</div>

This failed I looked for several examples I'm trying to do it without the use of javascript. In the End I just want to learn how to implement a Dropdownlist & save it to the database allot of the methods that I tried to implement failed in MVC5.

I'm not using any files I'm implementing I'm not using any external files or downloaded anything from nuget. What is the proper method to use a dropdownlist all the online materials use several methods. Some use IEnumerals but all fail — authy, Oct 12 '18 at 21:00
e.g. lets say I use public IENumerable CountryList where countrylist class contains ID, CountryName. If I use @Html.DropDownListFor(model => model.CountryList, new SelectList(Model.CountryList)). The error is Model.CountryList cannot convert from CountryList to IEnumerable — authy, Oct 12 '18 at 21:04
In your code above, change `public CountryList CountryList { get; set; }` to `public CountryList SelectedCountry { get; set; }` and then change your razor code to use `model => model.SelectedCountry` (also change the Bind attribute) — Erik Funkenbusch, Oct 12 '18 at 21:15
Yea I created something like IEnumerable CountryList CountryList{set; get;} & inside country list is the enum — authy, Oct 12 '18 at 21:18
Once again, IEnumerable is *NOT* an enum. DO NOT use IEnumerable with EnumDropDownListFor. What you're saying doesn't make any sense. What do you mean "inside country list is the enum"? An enum is already a collection of items, you wouldn't put it in another collection. — Erik Funkenbusch, Oct 12 '18 at 21:19
I had so many problems with cannot pass Models.CountryList to IEnumerables that I'm now just trying to find to use List. So same way just made CountryList SelectedCountry {get; set;} also used Dropdownlist instead of enumDropDownList. In CountryList I used public List country { get; set; } I still have the issue of cannot convert CountryList to ienumerable. I'm having problems with both enum and list way. should I just create the country list as a basic string forthe dropdownlist? — authy, Oct 12 '18 at 21:38
Now the probelm in Model.Country is System.NullReferenceException: 'Object reference not set to an instance of an object.' System.Web.Mvc.WebViewPage.Model.get returned null. Btw the database is populated with country names. — authy, Oct 12 '18 at 22:08

score 0 · Accepted Answer · answered Oct 13 '18 at 19:04

0

I would sugest you to add a html extension method that implement dropdownlist for a generic enumarator. Take a look at this answer.

answered Oct 13 '18 at 19:04

Matheus Valiente Souza

358
2
8

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

There is slightly change in your view where you bind the Country

this is actually you write

 @Html.EnumDropDownListFor(model => model.CountryList)

Change is need to add name property in your country list (it must be ID that is your taken in your model) , so it must be like this to maintain country list value

@Html.DropDownListFor(model => model.CountryList.Id, new SelectList(model => model.CountryList)

Becouse every HTML control need unique indentifier

Difficulties with DropDownlist in ASP.Net MVC5

2 Answers2

There is slightly change in your view where you bind the Country