MVC 4，复选框列表和我 [英] MVC 4, Checkbox list and me

问题描述

早上，所有的。

我可以看到这个已在别处讨论过，但不知道如果有什么改变了或事物在4 MVC像我这样简单的傻瓜？！

I can see this has been discussed elsewhere but was wondering if anything had change or things made simpler in MVC 4 for simpletons like me?!

场景

我有以下的，编辑的模式

public class CorporateDetails
{

    public Guid? Id { get; set; }

    [Key]
    public int CorporateDetailId { get; set; }

    public int? EmsId { get; set; }
    public string EmsName { get; set; }

    public virtual EmsType EmsType { get; set; }
}

public class EmsType
{
    [Key]
    public int? EmsId { get; set; }
    public string EmsName { get; set; }

    public virtual ICollection<EmsType> EmsTypes { get; set; }
}

通过以​​下标准创建查看

With the following standard create view:

 <fieldset>
    <legend>CorporateDetails</legend>



    <div class="editor-label">
        @Html.LabelFor(model => model.EmsId, "EmsType")
    </div>
    <div class="editor-field">
        @Html.DropDownList("EmsId", String.Empty)
        @Html.ValidationMessageFor(model => model.EmsId)
    </div>
    <div class="editor-label">
        @Html.LabelFor(model => model.EmsName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.EmsName)
        @Html.ValidationMessageFor(model => model.EmsName)
    </div>

    <p>
        <input type="submit" value="Create" />
    </p>
</fieldset>

这给了我，开箱，一个美丽的下拉列表一拉<的href=\"http://weblogs.asp.net/scottgu/archive/2011/05/05/ef-$c$c-first-and-data-scaffolding-with-the-asp-net-mvc-3-tools-update.aspx\">Scott顾的博客

This gives me, out of the box, a beautiful drop down list a la Scott Gu's blog

现在我真正的问题是这样的 - 我如何才能有效地转化这个下拉框究竟会有效地多选，多选列表

Now my real question is this - how can I effectively convert this drop down box to what will effectively be a multi select,checkbox list?

再次道歉去了老掉牙的话题，但我只是试水，看是否发生了任何更新。

Again, apologies for going over trodden ground but I was just testing the water to see if any updates have occurred.

请注意，第一个MVC项目，所以还是轻轻的，我感觉很厚又说：（

Please note, first MVC project so go gently, I'm feeling very thick again :'(

推荐答案

右键好吧，我有它排序 - 万岁！你可以从注释中看到，有迹象表明，想出了一些问题，但请找它不工作的完整解决方案如下：D

Right ok, I have got it sorted - hurrah! As you can see from the comments, there were a few issues that came up but please find below the complete solution which DOES work :D

型号

 public class CorporateDetails
    {

        public Guid? Id { get; set; }

        [Key]
        public int CorporateDetailId { get; set; }

        public int[] EmsId { get; set; }

        }

    public class EmsType
    {
        [Key]
        public int EmsId { get; set; }
        public string EmsName { get; set; }

        public virtual ICollection<EmsType> EmsTypes { get; set; }
    }

控制器

 public ActionResult Create()
    {
        CorporateDetails corporatedetails = new CorporateDetails();
        ViewBag.EmsId = new MultiSelectList(db.EmsTypes, "EmsId", "EmsName");
        return View(corporatedetails);
    }

扩展（放在一个文件夹在项目的根目录）

Extension (placed in a folder in the root of the project)

 public static MvcHtmlString CheckBoxListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty[]>> expression, MultiSelectList multiSelectList, object htmlAttributes = null)
    {
        //Derive property name for checkbox name
        MemberExpression body = expression.Body as MemberExpression;
        string propertyName = body.Member.Name;

        //Get currently select values from the ViewData model
        TProperty[] list = expression.Compile().Invoke(htmlHelper.ViewData.Model);

        //Convert selected value list to a List<string> for easy manipulation
        List<string> selectedValues = new List<string>();

        if (list != null)
        {
            selectedValues = new List<TProperty>(list).ConvertAll<string>(delegate(TProperty i) { return i.ToString(); });
        }

        //Create div
        TagBuilder divTag = new TagBuilder("div");
        divTag.MergeAttributes(new RouteValueDictionary(htmlAttributes), true);

        //Add checkboxes
        foreach (SelectListItem item in multiSelectList)
        {
            divTag.InnerHtml += String.Format("<div><input type=\"checkbox\" name=\"{0}\" id=\"{0}_{1}\" " +
                                                "value=\"{1}\" {2} /><label for=\"{0}_{1}\">{3}</label></div>",
                                                propertyName,
                                                item.Value,
                                                selectedValues.Contains(item.Value) ? "checked=\"checked\"" : "",
                                                item.Text);
        }

        return MvcHtmlString.Create(divTag.ToString());
    }

扩展在浏览网页配置注册

 <pages pageBaseType="System.Web.Mvc.WebViewPage">
  <namespaces>
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Optimization"/>
    <add namespace="System.Web.Routing" />
    <add namespace="MyProject.Extensions" />
  </namespaces>
</pages>

查看

@model Valpak.Websites.HealthChecker.Models.CorporateDetails
@{
    ViewBag.Title = "Create";
}
<h2>Create</h2>
@using (Html.BeginForm())
{
    @Html.ValidationSummary(true)

    <fieldset>
        <legend>CorporateDetails</legend>

           <div class="editor-label">
           @Html.CheckBoxListFor(model => model.EmsId, (MultiSelectList) ViewBag.EmsId)
          </div>          
        <p>
            <input type="submit" value="Create" />
        </p>
    </fieldset>
}
<div>
    @Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

这给了我的复选框可爱的名单。乌拉！

Which gives me a lovely list of check boxes. Hurrah!

达林感谢您的帮助，我已将此作为答案，但+50您的时间和精力。

Thanks Darin for your help, I've marked this as the answer but +50 for your time and effort.

这篇关于MVC 4，复选框列表和我的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！