我无法使用json在asp.net mvc5中保存图像

Question

我的文件上传无效。我想上传图片。 我已经在视图中创建了输入类型文件。  这是我的代码 -

[HttpPost]
public ActionResult AddOrEdit(tbl_employee emp)
{
    var getGender = db.tbl_gender.ToList();
    SelectList list = new SelectList(getGender, "gender_type", "gender_type", emp);
    ViewBag.genderList = list;

    if (emp.employee_image != null)
    {
        string fileName = Path.GetFileNameWithoutExtension(emp.imageFile.FileName);
        string extension = Path.GetExtension(emp.imageFile.FileName);
        fileName = fileName + extension;
        emp.employee_image = "~/Images/Employee/" + fileName;
        fileName = Path.Combine(Server.MapPath("~/Images/Employee/"), fileName);
        emp.imageFile.SaveAs(fileName); 
    }
    if (emp.employee_id == 0)
    {
        db.tbl_employee.Add(emp);
        db.SaveChanges();
        return Json(new { success = true, message = "Saved Successfully" }, JsonRequestBehavior.AllowGet);
    }
    else
    {
        db.Entry(emp).State = EntityState.Modified;
        db.SaveChanges();
        return Json(new { success = true, message = "Updated Successfully" }, JsonRequestBehavior.AllowGet);
    }     
}

这是我的tbl_employee.cs

public long employee_id { get; set; }
public string employee_image { get; set; }
public HttpPostedFileBase imageFile { get; set; }

这里有什么问题？