使用MVC C＃进行选择时，如何将下拉列表值传递给提交按钮上的参数

我有一个链接到模型的存储过程，并且在提交时，我试图将Value设为基于下拉列表的参数。将字符串放入参数中时，可以得到最终值。但是，我希望基于使用提交按钮进行选择的下拉列表的最终价值。请帮助我如何将下拉列表中的选定值传递给参数。我的参数是GetWACC（）@ oplocation，@ Industry，@ Date）。我尝试将列表传递给参数并转换为ToString（），但是它不起作用。请帮忙

非常感谢。

这是我的HomeController：

 public ActionResult WACC()
    {
        ViewBag.Message = "Your WACC page.";

        //Set Industry : Later make it DB-Driven
        //List<SelectListItem> lstIndustry = new List<SelectListItem>() {
        //    new SelectListItem {Text = "Financials", Value = "1"},
        //  new SelectListItem {Text = "Real Estate", Value = "2"},
        //};



        // Pre-set values
        var objWACC = new WACC();

        objWACC.ValuationDate = new DateTime(2018, 11, 20);
        //objWACC.IndustryList = lstIndustry;
        objWACC.IndustryList = WACC_Lib.GetIndustry();
        //objWACC.IndustrySelected = 1;
         objWACC.LocationList = WACC_Lib.GetOpLocations();
        //objWACC.LocationSelected = 1;
        DateTime waccdate = objWACC.ValuationDate;
        string indlist = objWACC.IndustryList.ToString();
        string loclist = objWACC.LocationList.ToString();
        objWACC.FairValue = WACC_Lib.GetWACC(loclist, indlist, waccdate);



        // Redirect to WACC page    
        return View(objWACC);
    }

这是我的WACC控制器：

public class WACCController : ApiController
{
    [HttpGet]
    [Route("GetWACC")] // for testing, F5 and change the link to http://localhost:54192/API/WACC/GetWACC?strOpLocation=Hong%20%Kong&strIndustry=Financials&strIniDate=2017-12-31&strValDate=2018-12-31 , the port no may be different (no "HOME")
    public double GetWACC(string strOpLocation, string strIndustry, DateTime ValDate)
    {
        double dblResult = 0.0;

        try
        {
            dblResult = BDODataLib.WACC_Lib.GetWACC(strOpLocation, strIndustry, ValDate);
        }
        catch
        {
            dblResult = -2.0;
        }            

        return dblResult;
    }
}

}

这是我的模特：

public class WACC
{
    [Key]
    [Display(Name = "Industry")]
    //public string Industry { get; set; }
    public List<SelectListItem> IndustryList { get; set; }
    public string IndustrySelected { get; set; }

   // public int LocID { get; set; }

    [Display(Name = "Location")]
    public List<SelectListItem> LocationList { get; set; }

    public string LocationSelected { get; set; }


    [Display(Name = "Valualtion Date")]
    public DateTime ValuationDate { get; set; }

    [Display(Name = "WACC")]
    public double FairValue { get; set; }
}

这是我的观点：

        <table class='wacctable'>


            <tr>
                <td style="background-color:lightgrey">@Html.DisplayNameFor(x => x.IndustryList)</td>
                @*<td>@Html.DropDownList("lstIndustry", (IEnumerable<SelectListItem>)ViewData["lstIndustry"],1)</td>*@
                @*<td style="width: 200px">@Html.DropDownListFor(x => x.IndustrySelected, Model.IndustryList, "--Select One--", new {onchange = "document.getElementById('TheForm').submit();" })</td>*@
                <td style="width: 200px">@Html.DropDownListFor(x => x.LocID, new SelectList (Model.IndustryList, "Value", "Text"), "--Select One--")</td>

                @*<td>@Html.DropDownListFor(model => model.Industry, (IEnumerable<SelectListItem>)ViewData["lstIndustry"])</td>*@
                @*<td>@Html.TextBoxFor(model => model.Industry)</td>*@
            </tr>
            <tr>
                <td style="background-color:lightgrey">@Html.DisplayNameFor(x => x.LocationList)</td>
                @*<td>@Html.TextBoxFor(x => x.LocationList)</td>*
                @*<td>@Html.DropDownListFor(x => x.LocationSelected, Model.LocationList, "--Select One--", new { @class = "abc", onchange = "document.getElementById('TheForm').submit();" })</td>*@
                <td>@Html.DropDownListFor(x => x.LocID, new SelectList (Model.LocationList, "Value", "Text"), "--Select One--", new { @class = "abc" })</td>


                @*<td>@Html.DropDownListFor(x => Model.LocationSelected, new SelectList(Model.LocationList, "Value"), htmlAttributes: new { @class = "form-control", id = "Location",style = "length: 180px;" })</td>*@

            </tr>
            <tr>
                <td style="background-color:lightgrey">@Html.DisplayNameFor(x => x.ValuationDate)</td>
                <td>@Html.TextBoxFor(x => x.ValuationDate, string.Format("{0:d}", Model.ValuationDate.ToString("yyyy-MM-dd")), new { @class = "date-picker", type = "date" })</td>
            </tr>
            <tr>
                <td style="background-color:lightgrey">@Html.DisplayNameFor(m => m.FairValue)</td>
                <td>@Html.TextBoxFor(m => m.FairValue, new { @class = "width: 180px;" })</td>
            </tr>

        </table>
        <br />
        <input type="submit" value='Submit' />




    }
</div>

这是我传递参数时的样子

The parameter return this "System.Collection.Generic.List"

这里的视图看起来像：

This is how the dropdownlist looks like