自定义查询不会通过视图模型传递给视图

Question

我有一个自定义查询，我想通过视图模型传递给视图。我可以将查询直接传递给视图并且它可以工作，但是当我尝试使用视图模型将它传递给视图时出现错误。我知道必须有一个简单的答案，但如果我能弄清楚我会被绞死的。

班级

 namespace TADSVer2_1.Models
{
  public class TailNo
  {
    public string TailNos { get; set; }
    public string Base { get; set; }
    public string ACType { get; set; }
  }
}

查询 查询工作正常，我得到了我需要的数据。

 var test3 = _context.Aircrafts.Where(c => c.BaseId == 4).Include(c => c.ACType).Include(c => c.Base)
            .Select(c => new TailNo {
              TailNos = c.TailNumber,
              ACType = c.ACType.Type,
              Base = c.Base.Name }).ToList();

景色

@model IEnumerable<TADSVer2_1.ViewModels.AircraftViewModel>
@{
  ViewBag.Title = "Index";
  Layout = "~/Views/Shared/_Layout.cshtml";
}
<ul>
   @foreach (var i in Model)
  {
    <li>
       @i.TailNos " " @i.Base " " @i.ACType
    </li>
  }
</ul>

上面的代码工作正常，但是当我使用视图模型时，我得到了如下所列的错误。

视图模型

namespace TADSVer2_1.ViewModels
{
  public class AircraftViewModel
  {
    public IEnumerable<TailNo> TailNo { get; set; }
  }

}

我收到的第一条错误消息是：

 'AircraftViewModel' does not contain a definition for 'TailNos' and no extension method     'TailNos' accepting a first argument of type 'AircraftViewModel' could be found (are you missing a      using directive or an assembly reference?)

所以我从视图中删除了 IEnumerable，我得到了这个错误：

  foreach statement cannot operate on variables of type 'AircraftViewModel' because 'AircraftViewModel' does not contain a public instance definition for 'GetEnumerator'

所以我替换了视图中的 IEnumerable 并在视图模型中尝试了这个并得到了这个编译错误

 public TailNo TailNo { get; set; }

     Error  CS1061  'AircraftViewModel' does not contain a definition for 'TailNos' and no   accessible extension method 'TailNos' accepting a first argument of type 'AircraftViewModel' could be found (are you missing a using directive or an assembly reference?)  TADSVer2_1  D:\Programing_ Examples\MVC_Examples\MVC Exercises\TADSVer2_1\TADSVer2_1\Views\Aircraft\Index.cshtml    12  Active

所以我被困在如何让自定义查询使用视图模型。感谢您的帮助。

Answer 1

试试这个：

@model TADSVer2_1.ViewModels.AircraftViewModel
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<ul>
    @foreach (var i in Model.TailNo)
    {
            <li>
                @i.TailNos " " @i.Base " " @i.ACType
            </li>
    }
</ul>

Answer 2

您正在浏览 AircraftViewModel 数据的 IEnumerable，然后该数据具有 TailNo 的 IEnumerable。你必须做一个嵌套的foreach（下面的例子）：

@model IEnumerable<TADSVer2_1.ViewModels.AircraftViewModel>
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<ul>
    @foreach (var i in Model)
    {
        @foreach (var tail in i.TailNo)
        {
            <li>
                @tail.TailNos " " @tail.Base " " @tail.ACType
            </li>
        }
    }
</ul>