asp.net-mvc - MVC 从数据库中填充下拉列表

Question

我对 MVC 很陌生。我试图用从数据库中检索到的货币填充下拉列表。我究竟做错了什么？

@model IEnumerable<DSABankSolution.Models.ExchangeRates>

@{
    ViewBag.Title = "Exchange Rates";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<br /> <br /> 


     <input type="text" size="5" value="1" />
        @Html.DropDownList("currency", Model.Select(p => new SelectListItem{ Text = p.Name, Value = p.ID})) 
        to  
       @Html.DropDownList("currency", Model.Select(p => new SelectListItem { Text = p.Name, Value = p.ID }));
    <br /> <br /> <input type="submit" name="Convert" />

汇率模型：

public class ExchangeRates
{
    public string ID { get; set; }
    public string Name { get; set; }
}

汇率控制器：

 public ActionResult Index()
    {
        IEnumerable<CommonLayer.Currency> currency = CurrencyRepository.Instance.getAllCurrencies().ToList();
        //ViewBag.CurrencyID = new SelectList(currency, "ID");
        //ViewBag.Currency = new SelectList(currency, "Name");

        return View(currency);
    }

货币库：

public List<CommonLayer.Currency> getAllCurrencies()
    {
        var query = from curr
                    in this.Entity.Currencies
                    select curr;

        return query.ToList();
    }

我得到的错误：

传递到字典中的模型项的类型为“System.Collections.Generic.List 1[CommonLayer.Currency]', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable1[D​​SABankSolution.Models.ExchangeRates]”。

谢谢！

Answer 1

错误说明了一切。Currency您正在返回此代码所示的集合

IEnumerable<CommonLayer.Currency> currency

然而你的观点期望作为一个集合ExchangeRates

@model IEnumerable<DSABankSolution.Models.ExchangeRates>

因此，您要么将视图中的声明更改为

@model IEnumerable<CommonLayer.Currency>

ExchangeRates或从您的控制器方法返回列表

Answer 2

您的视图需要类型的强类型模型

IEnumerable<DSABankSolution.Models.ExchangeRates>

然而，你正在路过

IEnumerable<CommonLayer.Currency> 

返回查看。