如何在asp.net mvc3中获取下拉列表的选定值？

Question

This is my code Display data from the database into DropDownList in asp.net MVC3 In this I can now display data from database into dropdownlist but now I want that if I select any thing from dropdownlist data I want that selected value pass in my stored procedure. I know there is same question might be available or has already been asked but I am not getting my answer which I want. If anyone can explain me step by step or provide me some useful links.

Answer 1

This code is not completly tested and implemented.

You can acheive it using onchange event of dropdownlist .

@Html.DropDownListFor(x => x.SelectedItemValue,new {@onchange="passvalue(this);"})

Handle it using javascript and ajax

<script type="text/javascript">
  function passvalue(e){
      $.ajax({
         type: 'POST',
         dataType: 'json',
         url: '@Url.Action("Index", "Home")',
         data: ({ selectedValue: e.innerHTML }),
         success: function (result) {
                                    },
         error: function (result) {
                    alert('error');
                }
      });
  }
  </script>

Now you can get the selected value to the controller

[HttpPost]
public ActionResult Index(int selectedValue)
{
   // do whatever you want with `selectedValue`
}

Hope it helps

Answer 2

This is a way to achieve this:

Subscribe the change event of the dropdown and call the action method(with ajax for example) that passes the selected value to the stored procedure.

Answer 3

There are several approaches. One of the simplest is to have a ViewModel with a collection of SelectListItems to render in the drop-down and an item to take the selection. In my example code below of course I am using hard-coded values etc to demo the point!

ViewModel

public class TestViewModel
{
    public IEnumerable<SelectListItem> TestListItems
    {
        get
        {
            return new List<SelectListItem>
            {
                new SelectListItem { Text = "Item 1", Value = "1" },
                new SelectListItem { Text = "Item 1", Value = "1" },
                new SelectListItem { Text = "Item 1", Value = "1" },
            };
        }
    }

    public string SelectedItemValue { get; set; }
}

View

<p>@Html.DropDownListFor(x => x.SelectedItemValue, new SelectList(Model.TestListItems, "Value", "Text"))</p>

Controller

public ActionResult Index()
{
    var viewModel = new TestViewModel();
    return View(viewModel);
}

[HttpPost]
public ActionResult Index(TestViewModel viewModel)
{
    string youChose = viewModel.SelectedItemValue;
    // ...
}

Also, to highlight the collection doesn't have to be of SelectListItem and could be another type. Then all you would need to do is change your view to perform a .Select to convert into a SelectListItem . For simplicity I've just made the ViewModel use it directly.