问题
I have been trying for three days, but I could not figure out the mistakes because the code is correct, but its implementation is not what I want. i am using three tables State,City and Donator,i want donator to select it's state and city when select state it display the specified city but when save its informatio the cityId don't save as in the image as at the end.
i use ap.net mvc 5 code first.
any one can help and tell me how to solve this problem the following my Models,Controller,and View:
public enum Gender
{ Male, Femal }
public class Donator
{
public int Id { get; set; }
public string Name { get; set; }
public Gender gender { get; set; }
public int Age { get; set; }
public string BloodType { get; set; }
public int StateId { get; set; }
public int CityId { get; set; }
[ForeignKey("StateId")]
public State state { get; set; }
}
//State Table
public class State
{
public int StateId { get; set; }
public string StateName { get; set; }
public ICollection<City> cities { get; set; }
public ICollection<Donator> donS { get; set; }
}
//City table
public class City
{
public int CityId { get; set; }
public string CityName { get; set; }
public int StateId { get; set; }
[ForeignKey("StateId")]
public State state { get; set; }
}
//Donators Controller
public class DonatorsController : Controller
{
private ApplicationDbContext db = new ApplicationDbContext();
// GET: Donators
public ActionResult Index()
{
return View(db.Donators.ToList());
}
// GET: Donators/Details/5
public ActionResult Details(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Donator donator = db.Donators.Find(id);
if (donator == null)
{
return HttpNotFound();
}
return View(donator);
}
// GET: Donators/Create
public ActionResult Create()
{
ViewBag.StateId = new SelectList(db.state, "StateId", "StateName");
return View();
}
// POST: Donators/Create
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "Id,Name,gender,Age,BloodType,CountryId,StateId")] Donator donator)
{
if (ModelState.IsValid)
{
db.Donators.Add(donator);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.StateId = new SelectList(db.state, "StateId", "StateName", donator.StateId);
return View(donator);
}
// GET: Donators/Edit/5
public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Donator donator = db.Donators.Find(id);
if (donator == null)
{
return HttpNotFound();
}
ViewBag.StateId = new SelectList(db.state, "StateId", "StateName", donator.StateId);
return View(donator);
}
// POST: Donators/Edit/5
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include = "Id,Name,gender,Age,BloodType,StateId,CityId")] Donator donator)
{
if (ModelState.IsValid)
{
db.Entry(donator).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.CountryId = new SelectList(db.country, "CountryId", "CountryName");
return View(donator);
}
// GET: Donators/Delete/5
public ActionResult Delete(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Donator donator = db.Donators.Find(id);
if (donator == null)
{
return HttpNotFound();
}
return View(donator);
}
// POST: Donators/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public ActionResult DeleteConfirmed(int id)
{
Donator donator = db.Donators.Find(id);
db.Donators.Remove(donator);
db.SaveChanges();
return RedirectToAction("Index");
}
public JsonResult StateList(int Id)
{
var state = from s in db.state
where s.CountryId == Id
select s;
return Json(new SelectList(state.ToArray(), "StateId", "StateName"), JsonRequestBehavior.AllowGet);
}
public JsonResult Citylist(int id)
{
var city = from c in db.city
where c.StateId == id
select c;
return Json(new SelectList(city.ToArray(), "CityId", "CityName"), JsonRequestBehavior.AllowGet);
}
public IList<State> Getstate(int CountryId)
{
return db.state.Where(m => m.CountryId == CountryId).ToList();
}
[AcceptVerbs(HttpVerbs.Get)]
public JsonResult LoadClassesByCountryId(string CountryName)
{
var stateList = this.Getstate(Convert.ToInt32(CountryName));
var stateData = stateList.Select(m => new SelectListItem()
{
Text = m.StateName,
Value = m.CountryId.ToString(),
});
return Json(stateData, JsonRequestBehavior.AllowGet);
}
}
//Create View
@model WebApplication6.Models.Donator
@{
Layout = "~/Views/Shared/_Layout.cshtml";
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Create</title>
</head>
<body>
@Scripts.Render("~/bundles/jquery")
@Scripts.Render("~/bundles/jqueryval")
<script type="text/jscript">
$(function () {
$('#State').change(function () {
$.getJSON('/Donators/Citylist/' + $('#State').val(), function (data) {
var items = '<option>Select a City</option>';
$.each(data, function (i, city) {
items += "<option value='" + city.Value + "'>" + city.Text + "</option>";
});
$('#city').html(items);
});
});
});
</script>
@using (Html.BeginForm())
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Donator</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.gender, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EnumDropDownListFor(model => model.gender, htmlAttributes: new { @class = "form-control" })
@Html.ValidationMessageFor(model => model.gender, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Age, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Age, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Age, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BloodType, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BloodType, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BloodType, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.StateId, "StateId", htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("StateId", null, htmlAttributes: new {id="State", @class = "form-control" })
@Html.ValidationMessageFor(model => model.StateId, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.CityId, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("City", new SelectList(string.Empty, "Value", "Text"), htmlAttributes: new { id = "city", @class = "form-control" })
@Html.ValidationMessageFor(model => model.CityId, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
</body>
</html>
donator create view:
after save donator info(index view)
回答1:
In your POST create controller action, you are not binding CityId. You're binding CountryId, is that a typo?
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "Id,Name,gender,Age,BloodType,CountryId,StateId,CityId")] Donator donator)
{
// add cityId to the bind parameters above
...
}
You'll need to update City to CityId on your html helper.
// please update first string parameter to CityId
@Html.DropDownList("CityId", new SelectList(string.Empty, "Value", "Text"), htmlAttributes: new { id = "city", @class = "form-control" })
来源：https://stackoverflow.com/questions/61212504/dropdown-list-with-ajax-generated-options-not-saving-for-cityid-property