【发布时间】：2015-03-09 06:11:28
【问题描述】：
两周以来，我一直在尝试创建一个包含 3 个下拉列表的 ASP.NET MVC 4 应用程序。 它们是 Country、State 和 City 。 我关注this article
我从数据库调用的这些数据库列表详细信息
连接字符串：
<connectionStrings>
<add name="CACD_Con" connectionString="metadata=res://*/Models.Project_Name.csdl|res://*/Models.Project_Name.ssdl|res://*/Models.Project_Name.msl;provider=System.Data.SqlClient;provider connection string="data source=192.168.0.000;initial catalog=CACD;persist security info=True;user id=000;password=000000000;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
</connectionStrings>
控制器类：
public class CacadingController : Controller
{
private ProjectContext db = new ProjectContext();
public ActionResult Index()
{
ViewBag.CountryId = new SelectList(db.Countrys, "CountryId", "CountryName");
return View();
}
public JsonResult StateList(int Id)
{
var state = from s in db.States
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.Citys
where c.StateId == id
select c;
return Json(new SelectList(city.ToArray(), "CityId", "CityName"), JsonRequestBehavior.AllowGet);
}
public IList<State> Getstate(int CountryId)
{
return db.States.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);
}
}
模型类：
public partial class ProjectContext : DbContext
{
public ProjectContext()
: base("CACD")
{
}
public DbSet<Country> Countrys { get; set; }
public DbSet<State> States { get; set; }
public DbSet<City> Citys { get; set; }
}
public class Country
{
[Key]
public int CountryId { get; set; }
public string CountryName { get; set; }
public virtual ICollection<State> States { get; set; }
}
public class State
{
[Key]
public int StateId { get; set; }
public string StateName { get; set; }
[ForeignKey("Country")]
public int CountryId { get; set; }
public virtual Country Country { get; set; }
public virtual ICollection<City> Citys { get; set; }
}
public class City
{
[Key]
public int CityId { get; set; }
public string CityName { get; set; }
[ForeignKey("State")]
public int StateId { get; set; }
public virtual State State { get; set; }
}
查看文件(cshtml)
@model Project_Name.Models.ProjectContext
@using (Html.BeginForm())
{
@Html.DropDownList("Country", ViewBag.CountryId as SelectList, "Select a Country", new { id="Country" })<br />
<select id="State" name="state"></select><br />
<select id="city" name="City"></select><br />
}
@Scripts.Render("~/bundles/jquery")
<script type="text/jscript">
$(function () {
$('#Country').change(function () {
$.getJSON('/Cascading/StateList/' + $('#Country').val(), function (data) {
var items = '<option>Select a State</option>';
$.each(data, function (i, state) {
items += "<option value='" + state.Value + "'>" + state.Text + "</option>";
});
$('#State').html(items);
});
});
$('#State').change(function () {
$.getJSON('/Cascading/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>
但是下拉菜单没有显示数据库中的任何数据，如果你能告诉我正确的路径真的很感激
【问题讨论】：
-
什么不起作用？是否填充了第一个下拉列表（国家/地区）？
-
并非上述任何一个 dropdwon 都不会填充任何内容
-
那么您需要调试您的代码 -
db.Countrys是否返回任何有效数据？ （你不需要在视图中@model AFFEMS2_HEC.Models.ProjectContext- 那不是你的模型！） -
它编译良好，没有任何错误，但是 db.Countrys 没有返回任何数据
标签： javascript c# jquery json asp.net-mvc