Trouble with ASP.NET MVC 3 DropDownListFor
本文关键字:DropDownListFor MVC NET with ASP Trouble | 更新日期: 2023-09-27 17:56:02
我一直在研究这个问题,但无法拼凑出适合我情况的答案。我感谢任何帮助。
我正在尝试创建一个下拉列表,该列表将在"创建任务"页面中显示应用程序名称,但将应用程序 ID 发布回数据库。目前,当我使用 DropDownList 时,我能够让应用程序名称正确显示在下拉列表中。但是,回发不起作用,我想改用DropDownListFor。另外,我正在使用Dictionary(int,String>,但我更喜欢使用IEnumerable。我一直在兜圈子,试图让DropDownListFor工作,但到目前为止没有运气。有谁知道我需要进行哪些更改?
"任务"模型:
using System;
using System.Collections.Generic;
using System.Web.Mvc;
namespace TaskCapture.Models
{
public class Task
{
public int TaskID { get; set; }
public string TaskDescription { get; set; }
public int ApplicationID { get; set; }
public virtual Application Application { get; set; }
}
}
"应用"模型:
using System;
using System.Collections.Generic;
namespace TaskCapture.Models
{
public class Application
{
public int ApplicationID { get; set; }
public string ApplicationName { get; set; }
public override string ToString()
{
return ApplicationName;
}
}
}
任务控制器:
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using TaskCapture.Models;
using TaskCapture.DAL;
namespace TaskCapture.Controllers
{
public class TaskController : Controller
{
private SupportContext db = new SupportContext();
//
// GET: /Task/Create
// get application names for listing in drop down
public Dictionary<int, String> GetApplications()
{
Dictionary<int, String> _applications = new Dictionary<int, String>();
var applicationsQuery =
from o in db.Applications
orderby o.ApplicationName
select o;
foreach (var c in applicationsQuery)
{
_applications.Add(c.ApplicationID, c.ApplicationName);
}
return _applications;
}
public ActionResult Create()
{
Dictionary<int, String> Applications = this.GetApplications();
ViewData["ApplicationList"] = new SelectList(Applications, "Key", "Value");
return View();
}
//
// POST: /Task/Create
[HttpPost]
public ActionResult Create(Task task)
{
try
{
if (ModelState.IsValid)
{
db.Tasks.Add(task);
db.SaveChanges();
return RedirectToAction("Index");
}
}
catch (DataException)
{
//Log the error (add a variable name after DataException)
ModelState.AddModelError("", "Unable to save changes. Try again....");
}
return View(task);
}
}
}
Task Create.cshmtl:
@model TaskCapture.Models.Task
@{
ViewBag.Title = "Create";
}
<h2>Create</h2>
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Task</legend>
<div class="editor-label">
@Html.LabelFor(model => model.Application.ApplicationName)
</div>
<div class="editor-field">
@Html.DropDownList("ApplicationList", (SelectList) ViewData["ApplicationList"])
@Html.ValidationMessageFor(model => model.Application.ApplicationName)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
任何帮助,不胜感激。如果我需要发布更多信息,请告诉我。谢谢。
我终于开始工作了。我需要创建一个新的应用程序对象:
@Html.DropDownListFor(model => model.ApplicationID, new TaskCapture.Models.Application().GetApplications())