Question

我在将ViewModel传递到视图时遇到问题。

我的ViewModel：

namespace ImpactDBASPNet.Models
{
    public class ComputerInfoViewModel
    {
        public List<string> CompanyList { get; set; }
        public tbl_computerinfo entitymodeleffort { get; set; }
    }
}

控制器：

    public ActionResult Index()
    {
        var tbl_computerinfo = db.tbl_computerinfo.Include(t => t.tbl_equipment);
        tbl_computerinfo = tbl_computerinfo.Where(c => c.Company == "Test Company");

        List<string> companylist = new List<string>();
        companylist.Add("Hello1");
        companylist.Add("hello2");

        ComputerInfoViewModel model = new ComputerInfoViewModel();
        model.CompanyList = companylist;
        model.entitymodeleffort = tbl_computerinfo;

        return View(model);
    }

我这样做主要是因为我需要在我的视图中传递下拉列表的列表，所以我需要传递实体框架模型和列表。我得到的错误是：

Error   1   Cannot implicitly convert type 'System.Linq.IQueryable<ImpactDBASPNet.Models.tbl_computerinfo>' to 'ImpactDBASPNet.Models.tbl_computerinfo'. An explicit conversion exists (are you missing a cast?)    c:\impactdbaspnet\controllers\tbl_computerinfocontroller.cs 31  39  ImpactPortal

Answer 1

属性entitymodeleffort的类型为tbl_computerinfo，但您为其分配了IEnumerable<tbl_computerinfo>，从而导致错误。您需要使用返回单个FirstOrDefault()对象的Single()（或其中一个变体 - tbl_computerinfo等）。

将代码更改为

public ActionResult Index()
{
  var tbl_computerinfo = db.tbl_computerinfo
   .Include(t => t.tbl_equipment)
   .Where(c => c.Company == "Test Company")
   .FirstOrDefault();
  List<string> companylist = new List<string>() { "Hello1", "Hello2" }; // save a few lines of code
  ComputerInfoViewModel model = new ComputerInfoViewModel();
  model.CompanyList = companylist;
  model.entitymodeleffort = tbl_computerinfo;
  return View(model);
}

附注：由于companylist用于dropdownlist，因此您可以设置属性SelectList

public SelectList CompanyList { get; set; }

和

model.CompanyList = new SelectList(companylist);

并在视图中

@Html.DropDownListFor(m => m.entitymodeleffort.SomeProperty, Model.CompanyList, ...)

ASP.Net将ViewModel传递给View（底层实体框架）

1 个答案: