Object reference not set to an instance of an object in Entity Framework - asp.net-mvc-5

Question

I got question on this error which I cannot solve. I am using Entity Framework database first. And before that I have deleted the entity model and create a new one. I am not sure it will affect or not.
This is my viewModel
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;
namespace MVCTutorial.Models
{
public class OtherIncViewModel
{
public virtual DbSet<User> Users { get; set; }
public virtual DbSet<UserGroup> UserGroups { get; set; }
public virtual DbSet<Patient> Patients { get; set; }
//User
public int UserId { get; set; }
public string UserFullName { get; set; }
public string UserIC { get; set; }
[DataType(DataType.Password)]
[Required(ErrorMessage = "This field is requiered.")]
public string UserPassword { get; set; }
public string UserEmail { get; set; }
public Nullable<int> UserGroupId { get; set; }
public string UserMMCRegistrationNo { get; set; }
[DisplayName("UserName")]
[Required(ErrorMessage = "This field is requiered.")]
public string UserLogin { get; set; }
public string UserFaxNo { get; set; }
public string UserDesignation { get; set; }
public string UserStatus { get; set; }
public string UserContact { get; set; }
public virtual UserGroup UserGroup { get; set; }
public string LoginErrorMessage { get; set; }
//Patient
public int PatientId { get; set; }
public string PatientName { get; set; }
public string PatientIC { get; set; }
public int PatientAge { get; set; }
public string PatientGender { get; set; }
public string Hospital { get; set; }
public string Ward { get; set; }
public string Department { get; set; }
public string Barcode { get; set; }
public string Race { get; set; }
public string PatientErrorMessage { get; set; }
public virtual ICollection<CaseOtherInc> CaseOtherIncs { get; set; }
public virtual ICollection<DraftCaseOtherInc> DraftCaseOtherIncs { get; set; }
}
}
This is my controller
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using MVCTutorial.Models;
namespace MVCTutorial.Controllers
{
public class WardStaffController : Controller
{
OtherIncContext db = new OtherIncContext();
// GET: WardStaff
public ActionResult Index() //Ward Staff Inbox
{
return View();
}
public ActionResult CreateTransfusion() //Ward Staff Create Transfusion
{
return View();
}
public ActionResult CreateIBCT() //Ward Staff Create IBCT
{
return View();
}
public ActionResult CreateNearMiss() //Ward Staff Create Near Miss
{
return View();
}
[HttpPost]
public ActionResult SearchPatient(MVCTutorial.Models.OtherIncViewModel patient)
{
using (OtherIncContext db = new OtherIncContext())
{ //I am wondering here why my local variable does not reference the namespace in this case is MVCTutorial. Is this why i get the null exception? I have check my database...i didn't have null record.
var patientDetails = db.Patients.Where(x => x.PatientIC == patient.PatientIC).FirstOrDefault();
if (patientDetails == null)
{
patient.PatientErrorMessage = "Please enter patient's IC number.";
return View("CreateOtherIncident", patient);
}
else
{
Session["PatientName"] = patientDetails.PatientName;
}
return RedirectToAction("CreateOtherIncident", "WardStaff");
}
}
This is my view
#model MVCTutorial.Models.OtherIncViewModel
#{
ViewBag.Title = "CreateOtherIncident";
Layout = "~/Views/Shared/_LayoutWardStaff.cshtml";
}
<h2>CreateOtherIncident</h2>
<h2>Reported By:</h2>
<p> Name: #Session["UserFullName"].ToString()</p>
<p>Email Address: #Session["UserEmail"].ToString()</p>
<p>Date:</p>
<p>Designation No.: #Session["UserDesignation"].ToString()</p>
<p>Tel.No: #Session["UserContact"].ToString()</p>
<p>Fax.No: #Session["UserFaxNo"].ToString()</p>
<h2>Patient Details:</h2>
#Html.LabelFor(model=>model.PatientIC)
#Html.EditorFor(model=>model.PatientIC)
<p>Patient Name: #Session["PatientName"].ToString()</p> //I get the exception here.
I suspect it is because of the local variable, but I cannot find any further error or exception on that.

Answer 1

Before the exception, To check session should not be null.
like:
#if (HttpContext.Current.Session["PatientName"] != null)
{ //#Session["PatientName"].ToString()
}