Asp.net mvc 5 没有类型为'；IEnumerable<；选择列表项>'；那有钥匙'；监督医师'；

在PatientViewModel中

 public IEnumerable<SelectListItem> SupervisingPhysician { get; set; }

错误：

没有“IEnumerable”类型的ViewData项具有键“SupervisingMedical”

---

可能存在与dupe稍有不同的错误消息的重复，但问题相同-这意味着

ViewBag。SupervisingMedicines

为

null

（可能是因为您在POST方法中返回了视图，但未重新分配

ViewBag

属性）。从第一个选择列表创建第二个完全相同的选择列表是没有意义的——它应该是

ViewBag.supervisingmedicines=listselectsplistems
// Supervising Physicians
List<SelectListItem> listSelectSPListItems = new List<SelectListItem>();
foreach (Physician physician in db.Physicians.Where(p => p.IsSupervising == true))
{
    SelectListItem selectSPList = new SelectListItem()
    {
        Text = physician.FirstName +" "+ physician.LastName,
        Value = physician.Id.ToString()
    };
    listSelectSPListItems.Add(selectSPList);
}
ViewBag.SupervisingPhysicians = new SelectList(listSelectSPListItems,"Value","Text");

@Html.DropDownListFor(x => x.SupervisingPhysician, (SelectList)ViewBag.SupervisingPhysicians, htmlAttributes: new { @class = "form-control col-md-4" })