Question

我想要一个包含3个值的下拉列表（超级用户-admin-user）这是角色

这是我的模特：

 public class LogIn
{
    public int ID { get; set; }
    [Required]
    [StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]
    [Display(Name = " username")]
    public string userame { get; set; }

    [Required]
    [StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]
    [DataType(DataType.Password)]
    [Display(Name = " password")]
    public string password { get; set; }
    public string role { get; set; }
}

这是我的观点（create.cshtml）：

@using (Html.BeginForm()) 
{
@Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>LogIn</h4>
    <hr />
    @Html.ValidationSummary(true)

    <div class="form-group">
        @Html.LabelFor(model => model.userame, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.userame)
            @Html.ValidationMessageFor(model => model.userame)
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.password, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.password)
            @Html.ValidationMessageFor(model => model.password)
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.role, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.role)
            @Html.ValidationMessageFor(model => model.role)
        </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>
}

这是我的LogInController：

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;
using MVCSports.Models;

namespace MVCSports.Controllers
{
public class LogInController : Controller
{
    private LogInDBContext db = new LogInDBContext();

    // GET: /LogIn/
    public ActionResult Index()
    {
        var list = new List<SelectListItem>
                   {
                       new SelectListItem { Text = "Admin", Value = "1" },
                       new SelectListItem { Text = "User", Value = "2" },
                       new SelectListItem { Text = "Someone else", Value = "3" }
                   };
        ViewBag.Roles = list;
        return View(db.sports.ToList());
    }
 // GET: /LogIn/Create
    public ActionResult Create()
    {
        return View();
    }

    // POST: /LogIn/Create
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include="ID,userame,password,role")] LogIn login)
    {
        if (ModelState.IsValid)
        {
            db.sports.Add(login);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        return View(login);
    }

这是index.cshtml：

@model IEnumerable<MVCSports.Models.LogIn>

@{
ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
@Html.ActionLink("Log In", "Create")
</p>

该角色不应该是一个文本字段，它应该是上面三个值的下拉列表，所选的值将保存在数据库中。这可能吗？

Answer 1

首先，当您第一次显示“登录”页面时，有些方法需要为下拉列表准备值，因此在ActionResult方法（而不是HttpPost !!）中，您将拥有：

var list = new List<SelectListItem>
                       {
                           new SelectListItem { Text = "Admin", Value = "1" },
                           new SelectListItem { Text = "User", Value = "2" },
                           new SelectListItem { Text = "Someone else", Value = "3" }
                       }; 
ViewBag.Roles = list;

然后在你看来你会有：

 <div class="form-group">
    @Html.LabelFor(model => model.role, new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.DropDownListFor(model => model.role, (IEnumerable<SelectListItem>)ViewBag.Roles)
        @Html.ValidationMessageFor(model => model.role)
    </div>
</div>

此代码将在视图中显示带有选项和用户答案的下拉列表将保存到模型中的角色字段。

MVC5下拉列表选择的项目

1 个答案: