C# 在MVC中设置DropDownList的默认值
我一直在四处寻找，但我找不到有人试图做我现在这样的事。我有几个模型在一个页面上一起工作。这些模型包括C# 在MVC中设置DropDownList的默认值,c#,asp.net,sql-server,asp.net-mvc,entity-framework,C#,Asp.net,Sql Server,Asp.net Mvc,Entity Framework,我一直在四处寻找，但我找不到有人试图做我现在这样的事。我有几个模型在一个页面上一起工作。这些模型包括员工1，电话管理器，以及电话类型 我已经设法让插入正常工作，但我似乎无法让编辑页面正常工作。我需要获取当前存储的phone\u type，它是phone\u type\u id的外键，并将其作为组合框中的默认项 我的模型是： [Table("employee.employees")] public partial class employees1 { public employees1(
员工1电话管理器电话类型phone\u typephone\u type\u id[Table("employee.employees")]
public partial class employees1
{
public employees1()
{
employee_email_manager = new List<email_manager>();
employee_employment_history = new HashSet<employment_history>();
employee_job_manager = new HashSet<job_manager>();
employee_phone_manager = new HashSet<phone_manager>();
this.salaries = new HashSet<salary>();
}
[Key]
public int employee_id { get; set; }
[Display(Name = "Employee ID")]
public int? assigned_id { get; set; }
[Display(Name = "Web User ID")]
public int? all_id { get; set; }
[Required]
[StringLength(50)]
[Display(Name = "First Name")]
public string first_name { get; set; }
[StringLength(50)]
[Display(Name = "Last Name")]
public string last_name { get; set; }
[Column(TypeName = "date")]
[Display(Name = "Birthday")]
[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
public DateTime birth_day { get; set; }
[Required]
[StringLength(1)]
[Display(Name = "Gender")]
public string gender { get; set; }
[Required]
[StringLength(128)]
[Display(Name = "Social")]
public string social { get; set; }
[Required]
[StringLength(128)]
[Display(Name = "Address")]
public string address_line_1 { get; set; }
[StringLength(50)]
[Display(Name = "Suite/Apt#")]
public string address_line_2 { get; set; }
[Required]
[StringLength(40)]
[Display(Name = "City")]
public string city { get; set; }
[Required]
[StringLength(20)]
[Display(Name = "State")]
public string state { get; set; }
[Required]
[StringLength(11)]
[Display(Name = "Zip")]
public string zip { get; set; }
[Column(TypeName = "date")]
[Display(Name = "Hire Date")]
[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
public DateTime hire_date { get; set; }
[Column(TypeName = "date")]
[Display(Name = "Separation Date")]
[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
public DateTime? termination_date { get; set; }
[StringLength(70)]
[Display(Name = "Emergency Contact Name")]
public string emergency_contact_name { get; set; }
[StringLength(15)]
[Display(Name = "Emergency Contact Number")]
public string emergency_contact_phone { get; set; }
[Display(Name = "Notes")]
public string notes { get; set; }
public virtual all_employees all_employees { get; set; }
[Display(Name = "Email Addresses")]
public virtual ICollection<email_manager> employee_email_manager { get; set; }
[Display(Name = "Employment History")]
public virtual ICollection<employment_history> employee_employment_history { get; set; }
[Display(Name = "Position History")]
public virtual ICollection<job_manager> employee_job_manager { get; set; }
[Display(Name = "Phone Numbers")]
public virtual ICollection<phone_manager> employee_phone_manager { get; set; }
internal void CreatePhoneNumbers(int count = 1)
{
for (int i = 0; i < count; i++)
{
employee_phone_manager.Add(new phone_manager());
}
}
[Table("employee.phone_manager")]
public partial class phone_manager
{
/*public phone_manager()
{
phone_types = new HashSet<phone_types>();
}*/
[Key]
public int phone_id { get; set; }
public int employee_id { get; set; }
[Required]
[StringLength(15)]
[Display(Name="Phone Number")]
public string phone_number { get; set; }
[StringLength(5)]
[Display(Name = "Extension")]
public string phone_extension { get; set; }
[Display(Name = "Type")]
public int phone_type { get; set; }
[Column(TypeName = "date")]
public DateTime date_added { get; set; }
public bool deleted { get; set; }
public virtual employees1 employees1 { get; set; }
[ForeignKey("phone_type")]
public virtual phone_types phone_types { get; set; }
//public virtual ICollection<phone_types> phone_types { get; set; }
}
[Table("employee.phone_types")]
public partial class phone_types
{
public phone_types()
{
phone_manager = new HashSet<phone_manager>();
}
[Key]
public int phone_type_id { get; set; }
[Required]
[StringLength(50)]
public string phone_type_name { get; set; }
public virtual ICollection<phone_manager> phone_manager { get; set; }
}
}
@Html.LabelFor(x => x.phone_type)
@Html.DropDownList("phone_type", string.Empty)
@Html.LabelFor(x => x.phone_number)
@Html.TextBoxFor(x => x.phone_number, new { @class = "phone", size = "10" })
@Html.LabelFor(x => x.phone_extension)
@Html.TextBoxFor(x => x.phone_extension, new { size = "4" })
@Html.HiddenFor(x => x.date_added, new { @Value = System.DateTime.Now })
@Html.HiddenFor(x => x.deleted, new { @class = "mark-for-delete" })
@Html.RemoveLink("Remove", "div.phoneNumber", "input.mark-for-delete")
这类事情给我带来了好几个小时的乐趣，尤其是在解决问题时 无论如何，下面将生成一个下拉列表，并选择模型中包含的值
@Html.DropDownListFor(x => x.phone_type, (SelectList)ViewBag.PhoneTypes)
如果愿意，您可以添加第三个参数，一个匿名对象，其方式与HiddenFor方法相同，用于样式设置。这类事情让我玩了好几个小时，尤其是在处理 无论如何，下面将生成一个下拉列表，并选择模型中包含的值
@Html.DropDownListFor(x => x.phone_type, (SelectList)ViewBag.PhoneTypes)
如果愿意，您可以添加第三个参数，一个匿名对象，其方式与HiddenFor方法相同，用于样式设置。这类事情让我玩了好几个小时，尤其是在处理 无论如何，下面将生成一个下拉列表，并选择模型中包含的值
@Html.DropDownListFor(x => x.phone_type, (SelectList)ViewBag.PhoneTypes)
如果愿意，您可以添加第三个参数，一个匿名对象，其方式与HiddenFor方法相同，用于样式设置。这类事情让我玩了好几个小时，尤其是在处理 无论如何，下面将生成一个下拉列表，并选择模型中包含的值
@Html.DropDownListFor(x => x.phone_type, (SelectList)ViewBag.PhoneTypes)
如果愿意，可以添加第三个参数，即匿名对象，方法与HiddenFor方法相同，用于样式设置。一个好的做法是不要使用ViewBag。尝试创建具有当前视图所需属性的简单模型 您还可以在对象为选定值的位置使用
SelectListViewBag.phonetype = new SelectList(db.phone_types, "phone_type_id", "phone_type_name", Model.phone_type );
注意：我已将ViewBag.phone\u类型更改为ViewBag.phone类型。一个好的做法是不要使用ViewBag。尝试创建具有当前视图所需属性的简单模型 您还可以在对象为选定值的位置使用
SelectListViewBag.phonetype = new SelectList(db.phone_types, "phone_type_id", "phone_type_name", Model.phone_type );
注意：我已将ViewBag.phone\u类型更改为ViewBag.phone类型。一个好的做法是不要使用ViewBag。尝试创建具有当前视图所需属性的简单模型 您还可以在对象为选定值的位置使用
SelectListViewBag.phonetype = new SelectList(db.phone_types, "phone_type_id", "phone_type_name", Model.phone_type );
注意：我已将ViewBag.phone\u类型更改为ViewBag.phone类型。一个好的做法是不要使用ViewBag。尝试创建具有当前视图所需属性的简单模型 您还可以在对象为选定值的位置使用
SelectListViewBag.phonetype = new SelectList(db.phone_types, "phone_type_id", "phone_type_name", Model.phone_type );
注意：我已将ViewBag.phone\u类型更改为ViewBag.phone类型。您可能需要在这里做更多的工作 循环浏览列表以构建下拉列表，并在点击时设置选定值 如果我误读了您的数据结构，请道歉，但这是理论： 控制器：
public ActionResult Create()
{
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id");
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
employee.CreatePhoneNumbers(1);
return View(employee);
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes,employee_phone_manager")] employees1 employees1)
{
if (ModelState.IsValid)
{
foreach (employees1.phone_manager phone in employees1.employee_phone_manager.ToList())
{
if (phone.deleted == true)
{
employees1.employee_phone_manager.Remove(phone);
}
}
db.employees1.Add(employees1);
db.SaveChanges();
return RedirectToAction("Index");
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// GET: /Employees/Edit/5
public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
employees1 employees1 = db.employees1.Find(id);
if (employees1 == null)
{
return HttpNotFound();
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// POST: /Employees/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes")] employees1 employees1)
{
if (ModelState.IsValid)
{
db.Entry(employees1).State = EntityState.Modified;
db.SaveChanges();
foreach (var item in employees1.employee_phone_manager)
{
db.Entry(item).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("Index");
}
var db2 = new LightHouseMain();
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
var phoneTypeList = new Dictionary<int, string>();
foreach (var pt in db.phone_types)
{
phoneTypeList.Add(pt.phone_type_id, phone_type_name);
if (pt.phone_type_id == employees1.phone_types.phone_type_id)
{
selectedValue = pt.phone_type_id;
}
}
你可能需要在这里做更多的举重 循环浏览列表以构建下拉列表，并在点击时设置选定值 如果我误读了您的数据结构，请道歉，但这是理论： 控制器：
public ActionResult Create()
{
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id");
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
employee.CreatePhoneNumbers(1);
return View(employee);
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes,employee_phone_manager")] employees1 employees1)
{
if (ModelState.IsValid)
{
foreach (employees1.phone_manager phone in employees1.employee_phone_manager.ToList())
{
if (phone.deleted == true)
{
employees1.employee_phone_manager.Remove(phone);
}
}
db.employees1.Add(employees1);
db.SaveChanges();
return RedirectToAction("Index");
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// GET: /Employees/Edit/5
public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
employees1 employees1 = db.employees1.Find(id);
if (employees1 == null)
{
return HttpNotFound();
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// POST: /Employees/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes")] employees1 employees1)
{
if (ModelState.IsValid)
{
db.Entry(employees1).State = EntityState.Modified;
db.SaveChanges();
foreach (var item in employees1.employee_phone_manager)
{
db.Entry(item).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("Index");
}
var db2 = new LightHouseMain();
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
var phoneTypeList = new Dictionary<int, string>();
foreach (var pt in db.phone_types)
{
phoneTypeList.Add(pt.phone_type_id, phone_type_name);
if (pt.phone_type_id == employees1.phone_types.phone_type_id)
{
selectedValue = pt.phone_type_id;
}
}
你可能需要在这里做更多的举重 循环浏览列表以构建下拉列表，并在点击时设置选定值 如果我误读了您的数据结构，请道歉，但这是理论： 控制器：
public ActionResult Create()
{
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id");
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
employee.CreatePhoneNumbers(1);
return View(employee);
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes,employee_phone_manager")] employees1 employees1)
{
if (ModelState.IsValid)
{
foreach (employees1.phone_manager phone in employees1.employee_phone_manager.ToList())
{
if (phone.deleted == true)
{
employees1.employee_phone_manager.Remove(phone);
}
}
db.employees1.Add(employees1);
db.SaveChanges();
return RedirectToAction("Index");
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// GET: /Employees/Edit/5
public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
employees1 employees1 = db.employees1.Find(id);
if (employees1 == null)
{
return HttpNotFound();
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// POST: /Employees/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes")] employees1 employees1)
{
if (ModelState.IsValid)
{
db.Entry(employees1).State = EntityState.Modified;
db.SaveChanges();
foreach (var item in employees1.employee_phone_manager)
{
db.Entry(item).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("Index");
}
var db2 = new LightHouseMain();
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
var phoneTypeList = new Dictionary<int, string>();
foreach (var pt in db.phone_types)
{
phoneTypeList.Add(pt.phone_type_id, phone_type_name);
if (pt.phone_type_id == employees1.phone_types.phone_type_id)
{
selectedValue = pt.phone_type_id;
}
}
你可能需要在这里做更多的举重 循环浏览列表以构建下拉列表，并在点击时设置选定值 如果我误读了您的数据结构，请道歉，但这是理论： 控制器：
public ActionResult Create()
{
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id");
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
employee.CreatePhoneNumbers(1);
return View(employee);
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes,employee_phone_manager")] employees1 employees1)
{
if (ModelState.IsValid)
{
foreach (employees1.phone_manager phone in employees1.employee_phone_manager.ToList())
{
if (phone.deleted == true)
{
employees1.employee_phone_manager.Remove(phone);
}
}
db.employees1.Add(employees1);
db.SaveChanges();
return RedirectToAction("Index");
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// GET: /Employees/Edit/5
public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
employees1 employees1 = db.employees1.Find(id);
if (employees1 == null)
{
return HttpNotFound();
}
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
// POST: /Employees/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes")] employees1 employees1)
{
if (ModelState.IsValid)
{
db.Entry(employees1).State = EntityState.Modified;
db.SaveChanges();
foreach (var item in employees1.employee_phone_manager)
{
db.Entry(item).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("Index");
}
var db2 = new LightHouseMain();
var employee = new employees1();
ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
return View(employees1);
}
var phoneTypeList = new Dictionary<int, string>();
foreach (var pt in db.phone_types)
{
phoneTypeList.Add(pt.phone_type_id, phone_type_name);
if (pt.phone_type_id == employees1.phone_types.phone_type_id)
{
selectedValue = pt.phone_type_id;
}
}
我可以补充一点，我最终放弃了ViewBag，因为我不喜欢失去强大的打字功能。相反，我在业务逻辑层中使用了各种静态方法，因此返回类型已经正确，不需要强制转换。感谢您的帮助！这确实解决了我在允许传递null值时遇到的一个问题，但它不会自动选择默认值，它仍然只选择第一个值。由于我是Asp.Net新手，我几乎感觉自己在胡言乱语：/啊，我认为这是因为ViewBag属性与模型的属性同名。尝试将ViewBag属性更改为PhoneTypes或类似内容。我编辑了答案来展示这一点。你在这一点上实际上是正确的！主要问题是由于命名冲突！我不知道为什么会这样！这是一个非常狡猾的问题，但由于这是我浪费大量时间的原因，这不是一个我容易忘记的问题！我可以补充一点，我最终放弃了ViewBag，因为我不喜欢失去强大的打字功能。相反，我在业务逻辑层中使用了各种静态方法，因此返回类型已经正确，不需要强制转换。感谢您的帮助！这确实解决了我在允许传递null值时遇到的一个问题，但它不会自动选择默认值，它仍然只选择第一个值。由于我是Asp.Net新手，我几乎感觉自己在胡言乱语：/啊，我认为这是因为ViewBag属性与模型的属性同名。尝试将ViewBag属性更改为PhoneTypes或类似内容。我已经编辑了答案