我是新手。我正在使用Northwind数据库。 REGION DESCRIPTIONS出现在下拉列表中，但是当我尝试创建新客户时，没有新记录保存到数据库中，因为下拉列表选择的值不起作用。这两个表未与模型中的外键链接。 有什么帮助？！谢谢你。
this is the view :
@model Northwind.Customer
@{
ViewBag.Title = "Create";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>Create</h2>
@using (Html.BeginForm(null, null, FormMethod.Post, new { enctype = "multipart/form-data" }))
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Customer</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.CustomerID, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.CustomerID, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.CustomerID, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.CompanyName, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.CompanyName, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.CompanyName, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ContactName, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.ContactName, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.ContactName, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ContactTitle, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.ContactTitle, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.ContactTitle, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Address, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Address, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Address, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.City, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.City, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.City, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Region, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("Region", String.Empty)
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.PostalCode, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.PostalCode, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.PostalCode, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Country, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Country, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Country, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Phone, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Phone, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Phone, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Fax, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Fax, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Fax, "", 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>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}
这是控制器：
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;
using Northwind.Models;
using System.Data.Entity;
using System.Data.Entity.Validation;
namespace Northwind.Controllers
{
public class CustomerController : Controller
{
dbNorthwindEntities db = new dbNorthwindEntities();
// GET: Customer
// public ActionResult Index()
// {
// return View(db.Customers.ToList().Take(10));
// return View(db.Customers.ToList());
// }
public ActionResult Index()
{
return View(db.Customers.ToList());
// var customers = db.Customers.Include(a => a.Region);
// return View(customers.ToList());
// var customers = db.Customers.Include(a => a.Region);
// return View(customers.ToList());
// var customers = db.Customers.Include("Region");
//return View(customers.ToList());
// return View(db.Customers.ToList());
}
//me marr formen per create
[HttpGet]
public ActionResult Create()
{
ViewBag.Region = new SelectList(db.Regions, "RegionDescription", "RegionDescription");
return View();
}
//me bo post ne databaze
[HttpPost]
public ActionResult Create(Customer customer)
{
if (ModelState.IsValid)
{
db.Customers.Add(customer);
try
{
db.SaveChanges();
}
catch (DbEntityValidationException ex)
{
foreach (var entityValidationErrors in ex.EntityValidationErrors)
{
foreach (var validationError in entityValidationErrors.ValidationErrors)
{
Response.Write("Property: " + validationError.PropertyName + " Error: " + validationError.ErrorMessage);
}
}
}
//return RedirectToAction("Index");
}
ViewBag.Region = new SelectList(db.Regions, "RegionDescription", "RegionDescription", customer.Region);
return View(customer);
}
//me marr formen me get
[HttpGet]
public ActionResult Edit(string id)
{
dbNorthwindEntities db = new dbNorthwindEntities();
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Customer customer = db.Customers.Find(id);
if (customer == null) { return HttpNotFound(); }
ViewBag.Region = new SelectList(db.Regions, "RegionDescription", "RegionDescription", customer.Region);
return View(customer);
}
//me postu
[HttpPost]
public ActionResult Edit([Bind(Include = "CustomerID,CompanyName,ContactName,Address,City,Region ,PostalCode, Country , Phone , Fax ")]Customer customer)
{
if (ModelState.IsValid)
{
db.Entry(customer).State = EntityState.Modified;
db.SaveChanges();
// return RedirectToAction("Index", new {id = selectedc})
return RedirectToAction("Index");
}
ViewBag.Region = new SelectList(db.Regions, "RegionDescription", "RegionDescription", customer.Region);
return View(customer);
}
// GET: /Employee/Delete/5
public ActionResult Delete(string id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Customer customer = db.Customers.Find(id);
if (customer == null)
{
return HttpNotFound();
}
return View(customer);
}
/// POST: /Employee/Delete/5
[HttpPost]
public ActionResult Deletee(string id)
{
Customer customer = db.Customers.Find(id);
db.Customers.Remove(customer);
db.SaveChanges();
return RedirectToAction("Index");
}
[HttpGet]
public ActionResult Details(string id)
{
dbNorthwindEntities db = new dbNorthwindEntities();
Customer customer = db.Customers.Single(x => x.CustomerID == id);
return View(customer);
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
db.Dispose();
}
base.Dispose(disposing);
}
}
}
这是客户和地区类：
//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated from a template.
//
// Manual changes to this file may cause unexpected behavior in your application.
// Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
namespace Northwind
{
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
public partial class Customer
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public Customer()
{
this.Orders = new HashSet<Order>();
this.CustomerDemographics = new HashSet<CustomerDemographic>();
}
public string CustomerID { get; set; }
public string CompanyName { get; set; }
public string ContactName { get; set; }
public string ContactTitle { get; set; }
public string Address { get; set; }
public string City { get; set; }
// [StringLength(15, MinimumLength = 3, ErrorMessage = "Invalid")]
// [MaxLength(15), MinLength(5)]
public virtual Region Regions { get; set; }
public string Region { get; set; }
public string PostalCode { get; set; }
public string Country { get; set; }
public string Phone { get; set; }
public string Fax { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Order> Orders { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<CustomerDemographic> CustomerDemographics { get; set; }
// public string Region { get; set; }
// [NotMapped]
// public List<Region> RegionList { get; set; }
//public Region Regionn { get; set; } // Navigation Property
//[NotMapped]
// public string RegionID { get; set; }
// [NotMapped]
// public List<Region> RegionList { get; set; }
// public int RegionID { get; set; }
}
}
//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated from a template.
//
// Manual changes to this file may cause unexpected behavior in your application.
// Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
namespace Northwind
{
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
public partial class Region
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public Region()
{
this.Territories = new HashSet<Territory>();
}
public int RegionID { get; set; }
public string RegionDescription { get; set; }
public Nullable<int> SelectId { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Territory> Territories { get; set; }
// public List<Customer> Customers { get; set; } // Navigation property
}
}
答案 0 :(得分：0)
您可能应该为您的视图使用模型。
您可以添加Customer，Region列表和SelectedRegionId。然后使用这样的东西：
Html.DropDownListFor(model => model.SelectedRegionId, Model.Regions.Select(x => new SelectListItem { Text = x.Name, Value = x.Id.ToString() }))问题似乎是您没有变量来存储所选区域（在我的示例中为SelectedRegionId）。