问题1

Question

我有一个模型类如下：

namespace MvcApplication1.Models
{
    public enum Sex { Male, Female };
    public class Person
    {
        public int Id { get; set; }
        public string Name { get; set; }

        [Required(ErrorMessage="Please select either Female or Male.")]
        public Sex? Sex { get; set; }
    }
}

Edit操作确实：

namespace MvcApplication1.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Edit()
        {
            var Person = new Person { Id = 1, Name = "Someone", Sex = Sex.Male };
            return View(Person);
        }
    }
}

问题1

如何标记Edit视图，以便有一个包含3个选项的下拉控件：“ - Select - ”，“Female”和“Male”。对于传递给视图的Person，必须选择“男性”。

问题2

如何构成Create视图并保留下拉控件默认选择“--Select - ”。

以下是Create操作：

 public ActionResult Create()
 {
       var Person = new Person();
       return View(Person);
 }

Answer 1

有一个good answer already on how to convert an Enum into a SelectList，但我会重复使用该代码内联到答案。

public ActionResult Edit()
{
    var Person = new Person { Id = 1, Name = "Someone", Sex = Sex.Male };
    List<object> values = new List<object>();
    values.Add(new { ID = "choose", Name = "--Select--" });
    values.AddRange(from Sex sex in Enum.GetValues(typeof(Sex))
            select new { ID = sex, Name = sex.ToString() });            
    ViewData["sexes"] = new SelectList(values, "Id", "Name", Person.Sex);
    return View(Person);
}

现在是Edit.cshtml视图：

@model Test.Models.Person

@{
    ViewBag.Title = "Edit";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Edit</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>Person</legend>

        @Html.HiddenFor(model => model.Id)

        <div class="editor-label">
            @Html.LabelFor(model => model.Name)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Name)
            @Html.ValidationMessageFor(model => model.Name)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Sex)
        </div>
        <div class="editor-field">            
            @Html.DropDownListFor(model => model.Sex, (SelectList)ViewData["sexes"])
            @Html.ValidationMessageFor(model => model.Sex)
        </div>

        <p>
            <input type="submit" value="Save" />
        </p>
    </fieldset>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

现在将表单发布到的控件操作：

[HttpPost]
public ActionResult Edit(Person person)
{
    var newName = person.Name;
    var newSex = person.Sex;

    return RedirectToAction("index", "home");
}

现在以调试模式运行项目，并在post-to Edit操作中的return RedirectToAction("index", "home");行中断。了解如何在视图中更改表单值，然后在发布到操作中执行您需要执行的操作？除了使用ViewData传递列表之外，还有其他选项，但它们使示例复杂化并且非常丰富。

Create操作如下所示：

public ActionResult Create()
{
    Person person = new Person();
    List<object> values = new List<object>();
    values.Add(new { ID = "choose", Name = "--Select--" });
    values.AddRange(from Sex sex in Enum.GetValues(typeof(Sex))
            select new { ID = sex, Name = sex.ToString() });
    ViewData["sexes"] = new SelectList(values, "Id", "Name");
    return View(person);
}

默认选择列表项将是第一个，因此它将显示“--Select--”作为默认选项。

如何在强类型视图中为包含可为空的枚举属性的模型使用Html.DropDownList？

问题1

问题2

1 个答案: