我有一个下拉列表的来源
@Html.DropDownListFor(m => m.PatientAppointmentID, ViewBag.AppointmentDate as List<SelectListItem>," - Select Appointment Date -",new { @class = "form-control" })
它的控制器方法是:
public ActionResult Create(int? Patient_id)
{
CreateBillViewModel model = new CreateBillViewModel();
if (Patient_id != null)
{
List<SelectListItem> AppointmentDates = (from p in db.tblPatientAppointments
where p.patient_id == Patient_id
select new SelectListItem
{
Text = p.AppointmentDate,
Value = p.ID.ToString()
}).ToList();
ViewBag.AppointmentDate = AppointmentDates;
}
return View(model);
}
它正确填充了下拉列表中的值,但是当我填写表单并在下拉列表中选择值时,它出现以下错误:
System.InvalidOperationException:'具有键'PatientAppointmentID'的ViewData项的类型为'System.Int32',但必须类型为'IEnumerable'。'
进一步提交表单时,值将存储在如下所示的会话中,我还希望保留URL中的下拉列表和患者ID以保留要在会话中添加的其他值
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(string nameValueInsert, string nameValueSubmit, CreateBillViewModel model)
{
var button = nameValueInsert ?? nameValueSubmit;
if (button == "Insert")
{
if (Session["templist"] == null)
{
List<PatientViewModel> lst = new List<PatientViewModel>();
lst.Add(new PatientViewModel()
{
PatientAppointmentID = Int32.Parse(Request.Form["PatientAppointmentID"]),
Amount = double.Parse(Request.Form["Amount"]),
Description = Request.Form["Description"]
});
Session["templist"] = lst;
}
else
{
List<PatientViewModel> lst = (List<PatientViewModel>)Session["templist"];
lst.Add(new PatientViewModel()
{
PatientAppointmentID = Int32.Parse(Request.Form["PatientAppointmentID"]),
Amount = double.Parse(Request.Form["Amount"]),
Description = Request.Form["Description"]
});
Session["templist"] = lst;
}
}
else
{
if (ModelState.IsValid)
{
string username = "";
HttpCookie cookie = HttpContext.Request.Cookies["AdminCookies"];
if (cookie != null)
{
username = Convert.ToString(cookie.Values["UserName"]);
}
tblPatientBill patientbill = new tblPatientBill();
patientbill.PatientAppointmentID = model.PatientAppointmentID;
patientbill.Amount = model.AmountTotal;
patientbill.Description = model.Note;
patientbill.Discount = model.Discount;
patientbill.CreatedAt = model.CreatedAt;
patientbill.CreatedBy = username;
patientbill.is_active = true;
db.tblPatientBills.Add(patientbill);
db.SaveChanges();
int PatientBill_ID = Convert.ToInt32(patientbill.ID);
List<PatientViewModel> lst = (List<PatientViewModel>)Session["templist"];
if (lst != null)
{
tblPatientBillDetail billdetail = new tblPatientBillDetail();
foreach (var item in lst)
{
billdetail.PatientBillID = PatientBill_ID;
billdetail.Amount = item.Amount;
billdetail.CreatedAt = DateTime.UtcNow;
billdetail.CreatedBy = username;
billdetail.Description = item.Description;
billdetail.is_active = true;
db.tblPatientBillDetails.Add(billdetail);
db.SaveChanges();
}
Session.Clear();
}
return RedirectToAction("Print", new { Billid = @PatientBill_ID });
}
}
return View(model);
}
如果其他人也遇到同样的情况,此问题的解决方案如下所示:在ViewModel中为下拉列表创建属性以从数据库中检索值并将所选值发送到db。
public class CreateBillViewModel
{
-------- --------
public IEnumerable<SelectListItem> PatientAppointmentDate { get; set; }
public int PatientAppointmentID { get; set; }
-------- --------
}
public ActionResult Create(int? Patient_id)
{
CreateBillViewModel model = new CreateBillViewModel();
if (Patient_id != null)
{
model.PatientAppointmentDate = (from p in db.tblPatientAppointments
where p.patient_id == Patient_id
select new SelectListItem
{
Text = p.AppointmentDate,
Value = p.ID.ToString()
}).ToList();
}
return View(model);
}
在这样的视图中检索它:
@Html.DropDownListFor(m => m.PatientAppointmentID, Model.PatientAppointmentDate ?? new List<SelectListItem>(), "- Select Appointment Date - ", new { @class = "form-control" })
提交表单时,如果您要打开同一页面,并且希望下拉菜单中的值相同,则在HTTPPOST中将其发送回,如下所示。
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(CreateBillViewModel model, int? Patient_id)
{
if (ModelState.IsValid)
{
//Save into db
}
model.PatientAppointmentDate = (from p in db.tblPatientAppointments
where p.patient_id == Patient_id
select new SelectListItem
{
Text = p.AppointmentDate,
Value = p.ID.ToString()
}).ToList();
}
return View(model);
}