EF 4.1 + MVC Dropdownlist issues
本文关键字:Dropdownlist issues MVC EF | 更新日期: 2023-09-27 18:11:36
所以首先我试图创建ViewData["whatever"]对象,就像一样
ViewData["Blah"] = new selectList("Do cool stuff");
这导致了一个错误,即int32不是IEnummerable(没什么(;
然后我尝试了另一种方法
List<SelectItem> coolList = db.Select(new selectItem("bunch of cool stuff"));
ViewData["Blah"] = coolLost;
这就产生了一个永远不会改变的selectedIndex。
现在是我的最后一次尝试。
我已将ICollections添加到我的模型中。已添加collectionId。
例如
public class Horse
{
public int Id { get; set; }
[Required(ErrorMessage = "Name is required")]
public string Name { get; set; }
[Required(ErrorMessage = "Gender is required")]
public int? GenderId { get; set; }
public string Color { get; set; }
public int? LegTypeId { get; set; }
public int? CharacterId { get; set; }
public int Hearts { get; set; }
public bool Retired { get; set; }
// Parents
public int? SireId { get; set; }
public int? DamId { get; set; }
// Internals
public int Stamina { get; set; }
public int Speed { get; set; }
public int Sharp { get; set; }
// Special
public int Dirt { get; set; }
// Externals
public int Start { get; set; }
public int Corner { get; set; }
public int OutOfTheBox { get; set; }
public int Competing { get; set; }
public int Tenacious { get; set; }
public int Spurt { get; set; }
//Genders
public virtual ICollection<Gender> Genders { get; set; }
//LegTypes
public virtual ICollection<LegType> LegTypes { get; set; }
//Characters
public virtual ICollection<Character> Characters { get; set; }
//Dams
public virtual ICollection<Horse> Dams { get; set; }
//Sires
public virtual ICollection<Horse> Sires { get; set; }
//Races
public virtual ICollection<Race> RaceResults { get; set; }
//Training
public virtual ICollection<Training> TrainingResults { get; set; }
}
以及在我的cshtml文件中。
<div class="editor-label">
@Html.LabelFor(horse => horse.GenderId)
</div>
<div class="editor-field">
@Html.DropDownListFor(horse => horse.GenderId, new SelectList(Model.Genders, "Id", "Name", Model.GenderId), "-- Fill Out --")
@Html.ValidationMessageFor(horse => horse.GenderId)
</div>
这只会给我一个错误,说我有一个空引用。
我太没主意了。
然后还有一个更好的,你可以在我的模型中看到。我有一份父系和母系的名单。
但他们都是马。我怎样才能把我所有的马都列入那个名单。
提前感谢你的任何建议,这将触发灯泡在我的头脑。
现在也在尝试:
var genders = horseTracker.Genders.Select(g => new SelectListItem { Text = g.Name, Value = g.Id.ToString() }).ToList();
var legtypes = horseTracker.LegTypes.Select(l => new SelectListItem { Text = l.Name, Value = l.Id.ToString() }).ToList();
var characters = horseTracker.Characters.Select(c => new SelectListItem { Text = c.Name, Value = c.Id.ToString() }).ToList();
var sires = horseTracker.Horses.Where(h => h.Gender.Equals("Male") && h.Retired.Equals(true)).Select(h => new SelectListItem { Text = h.Name, Value = h.Id.ToString() }).ToList();
var dams = horseTracker.Horses.Where(h => h.Gender.Equals("Female") && h.Retired.Equals(true)).Select(h => new SelectListItem { Text = h.Name, Value = h.Id.ToString() }).ToList();
ViewData["Genders"] = genders;
ViewData["LegTypes"] = legtypes;
ViewData["Characters"] = characters;
ViewData["Sires"] = sires;
ViewData["Dams"] = dams;
这给了我一个错误,说LinQ显然不能使用toString((,因为这是一个不安全的方法。
public ActionResult Create()
{
ViewData["Genders"] = new SelectList(horseTracker.Genders, "Id", "Name");
ViewData["LegTypes"] = new SelectList(horseTracker.LegTypes, "Id", "Name");
ViewData["Characters"] = new SelectList(horseTracker.Characters, "Id", "Name");
ViewData["Sires"] = new SelectList(horseTracker.Horses.Where(h => h.Gender.Name.Equals("Male") && h.Retired.Equals(true)), "Id", "Name");
ViewData["Dams"] = new SelectList(horseTracker.Horses.Where(h => h.Gender.Name.Equals("Female") && h.Retired.Equals(true)), "Id", "Name");
return View();
}
<div class="editor-label">
@Html.LabelFor(horse => horse.GenderId)
</div>
<div class="editor-field">
@Html.DropDownList("Id", (SelectList)ViewData["Genders"])
@Html.ValidationMessageFor(horse => horse.GenderId)
</div>
获取正在运行和填充的页面。而是在创造马上。所选值为null。
以下是如何在MVC3中使用下拉列表的简单示例。
您应该创建这样的视图模型:
public class HorseViewModel
{
[Required(ErrorMessage = "Please give the horse a name.")]
public string Name { get; set; }
[Required(ErrorMessage = "Please select a gender.")]
public int SelectedGenderId { get; set; }
public ICollection<Gender> Genders { get; set; }
}
在您的控制器中:
[HttpGet]
public ActionResult Horses()
{
var model = new HorseViewModel { Horses = db.Genders.ToList() }
return View(model);
}
在您的模型中:
@model MvcProject.Models.HorseViewModel
@using (Html.BeginForm()) {
<div class="editor-label>
@Html.LabelFor(m => m.Name)
</div>
<div class="editor-field>
@Html.EditorFor(m => m.Name)
@Html.ValidationMessageFor(m => m.Name)
</div>
<div class="editor-label>
@Html.LabelFor(m => m.SelectedGenderId)
</div>
<div class="editor-field>
@Html.DropDownListFor(m => m.SelectedGenderId,
new SelectList(Model.Genders, "Id", "DisplayName"),
"-- Select Gender --")
@Html.ValidationMessageFor(m => m.SelectedGenderId)
</div>
<p><input type="submit" value="Submit"/></p>
}
这应该会给你一个表格,将所选的性别id张贴回控制器。
实际上,
我修复了它,解决方案比我预期的要简单得多。
ViewData["Genders"] = new SelectList(horseTracker.Genders, "Id", "Name");
ViewData["LegTypes"] = new SelectList(horseTracker.LegTypes, "Id", "Name");
ViewData["Characters"] = new SelectList(horseTracker.Characters, "Id", "Name");
ViewData["Sires"] = new SelectList(horseTracker.Horses.Where(h => h.Gender.Name.Equals("Male") && h.Retired.Equals(true)), "Id", "Name");
ViewData["Dams"] = new SelectList(horseTracker.Horses.Where(h => h.Gender.Name.Equals("Female") && h.Retired.Equals(true)), "Id", "Name");
这个在cshtml 中
@Html.DropDownListFor(horse => horse.GenderId, (SelectList)ViewData["Genders"])