从Enum创建的MVC Razor DropDownList

2 回答

• 1

  您可以手动构建选择列表，如您的答案所示，或者您可以使用内置的Html帮助程序 Html.EnumDropDownListFor ，这将实现我认为您正在寻找的代码少得多 . 示例用法如下：

  public class MyViewModel
  {
      //Month is an enum here
      public Month Month { get; set; }
  }
  

  你的观点（ MonthExample.cshtml ）看起来像：

  @model MyProject.MyViewModel
  ...
  @using(Html.BeginForm("MonthExample", "ControllerName", FormMethod.Post))
  {
      @Html.EnumDropDownListFor(x => x.Month)
      <button type="submit">Save</button>
  }
  
  ...
  

  框架将看到Month是一个枚举，并自动为下拉列表构建选项，而不是手动执行 .

  如果您想看一个控制器get / post的简单示例，它们可能如下所示：

  public ActionResult MonthExample()
  {
      return View(new MyViewModel());
  }
  
  [HttpPost]
  public ActionResult MonthExample(MyViewModel model)
  {
      //here model.Month will have the selected month from the dropdown list
  }
  

  回复于 2024-04-30T15:32:53+08:00
• 0

  所以在真正停下来思考错误后我已经解决了我的问题 . 那么实际上有两个我会解释 .

  我收到的错误是：

  System.Web.HttpException：'DataBinding：'ShiftPatternConfigurator.Models.Month'不包含名为'Month'的属性 .

  这让我想到我的枚举没有dataValueField或dataTypeField，因为它是枚举 .

  所以我查看了我创建SelectList的代码：

  ViewBag.Month = new SelectList(Enum.GetValues(typeof(Month)), "Month", "Month", DateTime.Now.ToString("MMMM"));
  

  我仔细查看了重载的方法，发现了一个不需要dataValueField或dataTypeField的方法，因此我将代码修改为以下内容：

  ViewBag.Month = new SelectList(Enum.GetValues(typeof(Month)), DateTime.Now.ToString("MMMM"));
  

  然后，这允许渲染DropDownList . 但是，我仍然遇到一个问题，即没有设置Selected值 . 快速谷歌后我发现你不能设置ViewBags动态字段与models属性相同 .

  所以我修改了我的控制器代码：

  ViewBag.MonthFilter = new SelectList(Enum.GetValues(typeof(Month)), DateTime.Now.ToString("MMMM"));
  

  和我的视图代码如下：

  @using (Html.BeginForm("SelectMonth", "HomeController", FormMethod.Post, new { enctype = "multipart/form-data" }))
  {
      @Html.DropDownList("Month", (SelectList)ViewBag.MonthFilter)
      <input type="submit" value="SelectMonth" />
  }
  

  编辑：这是我使用@GregH提供的答案后的新更新代码

  型号：

  using System;
  using System.Collections.Generic;
  
  namespace ShiftPatternConfigurator.Models
  {
      // view model
      public class ShiftViewModel
      {
          public IEnumerable<ShiftModel> Shifts { get; set; }
          public Month Month { get; set; }
      }
  
      // shift model
      public class ShiftModel
      {
          public int ShiftNo;
          public string ShiftName;
          public DateTime StartTime;
          public DateTime FinishTime;
          public string Team;
          public int Week;
          public int CycleWeek = 0;
          public string StartDay;
          public DateTime StartDate;
      }
  
      // month enum
      public enum Month
      {
          January = 1,
          February = 2,
          March = 3,
          April = 4,
          May = 5,
          June = 6,
          July = 7,
          August = 8,
          September = 9,
          October = 10,
          November = 11,
          December = 12
      }
  }
  

  控制器：

  using Oracle.ManagedDataAccess.Client;
  using ShiftPatternConfigurator.Models;
  using System;
  using System.Collections.Generic;
  using System.Text;
  using System.Web.Mvc;
  
  namespace ShiftPatternConfigurator.Controllers
  {
      public class HomeController : Controller
      {
          // GET: Index
          public ActionResult Index()
          {
              ViewBag.Title = "Shift Pattern Configurator Test";
              ShiftViewModel view = new ShiftViewModel
              {
                  Month = new Month()
              };
              view.Month = (Month)DateTime.Now.Month;
              view.Shifts = GetShiftData(view.Month);       
              return View(view);
          }
  
          [HttpPost]
          public ActionResult Index(ShiftViewModel view)
          {
              ViewBag.Title = "Shift Pattern Configurator";
              view.Shifts = GetShiftData(view.Month);
              return View(view);
          }
  
          private List<ShiftModel> GetShiftData(Month month)...
      }
  }
  

  查看：

  @model ShiftPatternConfigurator.Models.ShiftViewModel
  
  <h2>@ViewBag.Title</h2>
  
  @using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
  {
      @Html.EnumDropDownListFor(x => x.Month)
      <input type="submit" value="SelectMonth" />
  }
  <table class="table">
      <tr>
          <th>Shift No</th>
          <th>Shift Name</th>
          <th>Start Time</th>
          <th>Finish Time</th>
          <th>Team</th>
          <th>Week</th>
          <th>Start Day</th>
          <th>Start Date</th>
          <th></th>
      </tr>
  
      @if (Model.Shifts.Count() > 0)
      {
          foreach (var item in Model.Shifts)
          {
              <tr>
                  <td>@item.ShiftNo</td>
                  <td>@item.ShiftName</td>
                  <td>@item.StartTime</td>
                  <td>@item.FinishTime</td>
                  <td>@item.Team</td>
                  <td>@item.Week</td>
                  <td>@item.StartDay</td>
                  <td>@item.StartDate.ToShortDateString()</td>
                  <td>
                      @Html.ActionLink("Edit", "Edit", new { /* id=item.PrimaryKey */ }) |
                      @Html.ActionLink("Details", "Details", new { /* id=item.PrimaryKey */ }) |
                      @Html.ActionLink("Delete", "Delete", new { /* id=item.PrimaryKey */ })
                  </td>
              </tr>
          }
      }
      else
      {
          <tr>
              <td colspan="10" align="center"><h2>No Data</h2></td>
          </tr>
      }
  
  </table>
  

  回复于 2024-04-30T15:32:53+08:00