jQuery从多选择列表中获取值，如果语句MVC3

Question

I am trying to iterate through the list of values populating my select box, then set up a string based on the outcome. The string should contain a 1 for each selected item, and a zero for each item that isn't selected. I had been trying to use #Select option:selected to check that, but then found out that that selects all the options that are selected, so that just gives me all 1s in my string. Below is my select box:

<select multiple="multiple" id="Select">
    @foreach (var val in Model.SelectStuff)
    {
        <option value="@val.Key">@val.Descript</option>
    }
</select>

And the JQuery:

var admaList = "";

$("#Select option").each(function () {
    if ($("#Select option:selected")) {  //I know this doesn't work!
        list += "1,";
    }
    else {
        list += "0,";
    }
});

So, 2 questions. One, is how can I utilize this (if its possible), and is there a list that I could use in JQuery instead of passing back a string to the control that I am going to have to break into a list later anyway?

Answer 1

$('#Select').val() returns an array of the selected options from the multiple select element.

http://api.jquery.com/val/

So, in your case, I'm not sure if a string of 0's and 1's is actually what you want. If, for example, the "value" of the options are ids then take:

<select id="Select" multiple="multiple">
    <option value="1">Value 1</option>
    <option value="2">Value 2</option>
    <option value="3">Value 3</option>
</select>

If 1 and 3 are selected, then

$('#Select').val() // returns [1,3]

If you want to pass that to the server, then

var selectedValues = $('#Select').val() || [];
selectedValues.join(","); // return "1,3"

Answer 2

Have your tried not using jquery like this. It is possible to do it with jquery but a view model can also be used. In the view you can wire a List of selected values to your listbox. The user will be able to pick one or more options and it will automatically populate the selected values. Below is an example. Also I typed this without really compiling but i hope you get the idea.

View

@Model SelectStuff

 @using (Html.BeginForm("Index","Home",FormMethod.Post))
        {
            @Html.ValidationSummary(true)
            @Html.ListBox("SelectStuffSelected", Model.SelectStuff, new { @class = "whatever here" })
       // NOTE!!!!PAY ATTENTION HERE SelectStuffSelected will be used in the viewmodel!!!!!


                <p >
                    <input type="submit" value="Submit" />
               </p> 
    }

Controller

public ActionResult index()
return view();
[HttpPost]
public ActionResult(SelectStuff model)
{
  return view(model);
}

ViewModel

  public class SelectStuff
    {
    public SelectStuff(){InitialSignature();}

private void InitialSignature()
        {
            List<SelectListItem> IntialSignatureRaw = new List<SelectListItem>();
            IntialSignatureRaw.Add(new SelectListItem
            {
                Text = "Yes",
                Value = "1",
                Selected = true
            });


            IntialSignatureRaw.Add(new SelectListItem
            {
                Text = "No",
                Value = "0"
            });

            SelectStuff= new SelectList(IntialSignatureRaw, "Value", "Text");
        }
//here comes the magic 
        public virtual MultiSelectList SelectStuff {get;set;}
        public virtual List<string> SelectStuffSelected{get;set;}
      //PAY ATTENTION HERE!!!!! do you see SelectStuffSelected is wired to the view above?
}