how to get value of SelectListItem[]

Question

i need to get value of many select list with one name in asp.net core

I fill in a table using the loop and display it. The thing is that in each row of the table there is a series of item in select lists that have fixed values ​​that are filled for each row of the table.

And the next thing is that when posting the page, I need to know what value the user has selected in each row from the select list item

That means I need both the table row number and the value selected.

The main problem is that these select lists of items are also names, I can not give a name for each, because I do not have other names when taking it back

Thanks for telling me how I can fix this

   <tbody>
       @foreach (var item in allQuestion)
          {
            <tr>
                <td>@item.Question_Title</td>
                <td>@item.Answere1</td>
                <td>@item.Question_type</td>
                <td>
                    <select id="trueRate[@item.Question_ID]" class="form-control">
                      @foreach (var rate in TrueRate)
                      {
                          <option value="@rate.Value">@rate.Text</option>
                      }
                    </select>
                 </td>
              </tr>
           }
    </tbody>

Maybe I explained badly. I want to create an array from a list of numbers. This array must be repeated in each row of the table , And the user selects a value from this list for each row of the table. Now my problem is that I do not know how to create this array so that its name is available to me and the next problem is that I do not know how to get the value of the code. Keep in mind that this list of numbers is repeated for each row of the table and I need them all on the code side.

Answer 1

Actually, There is some difficulty in understanding your needs. But From your question and code, I guess you want to use foreach() to traverse your model, Then in each item, you want to nest a dropdown list, So i write a simple demo here, Hope it is what you want.

Model

public class Question
    {
        public int Id { get; set; }
        public string QuestionName { get; set; }
        public string QuestionType { get; set; }
        public string answers { get; set; }
    }

 public class Answer
    {
        public string Text { get; set; }

        public float Value { get; set; }
    }

Controller

public IActionResult Create()
        {

            //For testing convenience, I just hard code here
            List<Question> questions = new List<Question>()
            {
                new Question{
                    Id = 1,
                    QuestionName = "Question1",
                    QuestionType = "TypeA",

                },
                new Question{
                    Id = 2,
                    QuestionName = "Question2",
                    QuestionType = "TypeB",

                },
                new Question{
                    Id = 3,
                    QuestionName = "Question3",
                    QuestionType = "TypeC",

                },new Question{
                    Id = 4,
                    QuestionName = "Question4",
                    QuestionType = "TypeD",

                },
                new Question{
                    Id = 5,
                    QuestionName = "Question5",
                    QuestionType = "TypeE",

                }
            };

            List<Answer> answers = new List<Answer>()
            {
                  new Answer{
                Text = "AAAA",
                Value = 0.2F
             },
              new Answer{
                Text = "BBBB",
                Value = 0.3F
             },
               new Answer{
                Text = "CCCC",
                Value = 0.4F
             },
                new Answer{
                Text = "DDDD",
                Value = 0.5F
             }
            };


            List<SelectListItem> model = new List<SelectListItem>();
            foreach(var item in answers)
            {
                model.Add(new SelectListItem() { Text = item.Text,Value = item.Value.ToString()});
            }

            ViewBag.drop = model;

            return View(questions);
        }


[HttpPost]
        public IActionResult Create(List<Question> model)
        {
            float result=0;
            foreach (var item in model)
            {
               
                float data = float.Parse(item.answers);
                result += data;

            }

           //........
            
        }

View

@model List<Question>
@{
    var i = 0;
}

<form method="post">
    <table border="1">
        <tbody>
            @foreach (var item in @Model)
            {
                <tr >
                    <td>
                        @item.Id
                        <input type="hidden" asp-for="@Model[i].Id">
                    </td>
                    <td>
                        @item.QuestionName
                        <input type="hidden" asp-for="@Model[i].QuestionName">
                    </td>
                    <td>
                        @item.QuestionType
                         <input type="hidden" asp-for="@Model[i].QuestionType">
                    </td>
                    <td>
                        <select asp-for="@Model[i].answers" asp-items="@ViewBag.drop" class="form-control"></select>
                    </td>
                </tr>

                i++;
            }
        </tbody>
    </table>
    <button type="submit">submit</button>
</form>

Demo:

Then you can see it get the value of what you selected successfully.