MVC批量更新,可验证并解决集合元素不连续控制器接收不完全的问题

    public class User

    {

        public int Id { get; set; }

        [Required]

        public string Name { get; set; }

        public IList<Movie> FavouriteMovies { get; set; }

    }

    public class Movie

    {

        [Required]

        public string Title { get; set; }

        public int Rating { get; set; }

    } 

    public class HomeController : Controller

    {

        private static User _currentUser;

        private static User CurrentUser

        {

            get

            {

                if (_currentUser == null)

                {

                    _currentUser = GetFakeUser();

                }

                return _currentUser;

            }

            set { _currentUser = value; }

        }

        private static User GetFakeUser()

        {

            return new User()

            {

                Id = 1,

                Name = "darren",

                FavouriteMovies = new List<Movie>()

                {

                    new Movie(){Title = "movie1"},

                    new Movie(){Title = "movie2"},

                    new Movie(){Title = "movie3"}

                }

            };

        }

        public ActionResult EditUser()

        {

            return View(CurrentUser);

        }

        [HttpPost]

        public ActionResult EditUser(User user)

        {

            if (!ModelState.IsValid)

            {

                return View(user);

            }

            CurrentUser = user;

            return View(CurrentUser);

        }

        //响应视图添加按钮，通过部分视图生成一行

        public ActionResult MovieEntryRow()

        {

            return PartialView("MovieEntryEditor");

        }     

@using VariableCollection.Models

@model VariableCollection.Models.User

@{

    ViewBag.Title = "EditUser";

    Layout = "~/Views/Shared/_Layout.cshtml";

}

@using (Html.BeginForm())

{

    @Html.ValidationSummary(true)

    <fieldset>

        <legend>用户及喜欢电影</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>

    </fieldset>

    <fieldset>

        <legend>我最喜欢的电影</legend>

        @if (Model.FavouriteMovies == null || Model.FavouriteMovies.Count == 0)

        {

            <p>没有喜欢的电影~~</p>

        }

        else

        {

            <ul id="movieEditor" style="list-style-type: none">

                @foreach (Movie movie in Model.FavouriteMovies)

                {

                    Html.RenderPartial("MovieEntryEditor", movie);

                }

            </ul>

            <a id="addAnother" href="#">添加行</a>

        }

    </fieldset>

    <p>

        <input type="submit" value="提交"/>

    </p>

}

@section scripts

{

    <script type="text/javascript">

        $(function() {

            $(‘#movieEditor‘).sortable();

            $("#addAnother").click(function () {

                $.get(‘/Home/MovieEntryRow‘, function (template) {

                    $("#movieEditor").append(template);

                });

            });

        });

    </script>

}

using System;

using System.Collections.Generic;

using System.Web;

using System.Web.Mvc;

namespace VariableCollection.Extension

{

    public static class CollectionEditingHtmlExtensions

    {

        /// <summary>

        /// 目标是生成如下格式

        ///<input autocomplete="off" name="FavouriteMovies.Index" type="hidden" value="6d85a95b-1dee-4175-bfae-73fad6a3763b" />

        ///<label>Title</label>

        ///<input class="text-box single-line" name="FavouriteMovies[6d85a95b-1dee-4175-bfae-73fad6a3763b].Title" type="text" value="Movie 1" />

        ///<span class="field-validation-valid"></span>

        /// </summary>

        /// <typeparam name="TModel"></typeparam>

        /// <param name="html"></param>

        /// <param name="collectionName">集合属性的名称</param>

        /// <returns></returns>

        public static IDisposable BeginCollectionItem<TModel>(this HtmlHelper<TModel> html, string collectionName)

        {

            string itemIndex = Guid.NewGuid().ToString();

            //比如，FavouriteMovies[6d85a95b-1dee-4175-bfae-73fad6a3763b]

            string collectionItemName = string.Format("{0}[{1}]", collectionName, itemIndex);

            TagBuilder indexField = new TagBuilder("input");

            indexField.MergeAttributes(new Dictionary<string, string>() {

                { "name", String.Format("{0}.Index", collectionName) }, //name="FavouriteMovies.Index"

                { "value", itemIndex },//value="6d85a95b-1dee-4175-bfae-73fad6a3763b"

                { "type", "hidden" },

                { "autocomplete", "off" }

            });

            html.ViewContext.Writer.WriteLine(indexField.ToString(TagRenderMode.SelfClosing));

            return new CollectionItemNamePrefixScope(html.ViewData.TemplateInfo, collectionItemName);

        }

         private class CollectionItemNamePrefixScope : IDisposable

         {

             private readonly TemplateInfo _templateInfo;

             private readonly string _previousPrefix;

             public CollectionItemNamePrefixScope(TemplateInfo templateInfo, string collectionItemName)

             {

                 this._templateInfo = templateInfo;

                 _previousPrefix = templateInfo.HtmlFieldPrefix;

                 templateInfo.HtmlFieldPrefix = collectionItemName;

             }

             public void Dispose()

             {

                 _templateInfo.HtmlFieldPrefix = _previousPrefix;

             }

         }

    }

}

@using VariableCollection.Extension

@model VariableCollection.Models.Movie

<li style="padding-bottom: 15px;">

    @using (Html.BeginCollectionItem("FavouriteMovies"))

    {

        <img src="@Url.Content("~/Content/images/draggable-icon.png")" style="cursor: move" alt=""/>

        @Html.LabelFor(model => model.Title)

        @Html.EditorFor(model => model.Title)

        @Html.ValidationMessageFor(model => model.Title)

        @Html.LabelFor(model => model.Rating)

        @Html.EditorFor(model => model.Rating)

        @Html.ValidationMessageFor(model => model.Rating)

        <a href="#" onclick=" $(this).parent().remove(); ">删除行</a>

    }

</li>

using System;

using System.Collections.Generic;

using System.Web;

using System.Web.Mvc;

namespace VariableCollection.Extension

{

    public static class CollectionEditingHtmlExtensions

    {

        public static IDisposable BeginCollectionItem<TModel>(this HtmlHelper<TModel> html, string collectionName)

        {

            string collectionIndexFieldName = String.Format("{0}.Index", collectionName);//FavouriteMovies.Index

            string itemIndex = GetCollectionItemIndex(collectionIndexFieldName);

            //比如，FavouriteMovies[6d85a95b-1dee-4175-bfae-73fad6a3763b]

            string collectionItemName = string.Format("{0}[{1}]", collectionName, itemIndex);

            TagBuilder indexField = new TagBuilder("input");

            indexField.MergeAttributes(new Dictionary<string, string>() {

                { "name", String.Format("{0}.Index", collectionName) }, //name="FavouriteMovies.Index"

                { "value", itemIndex },//value="6d85a95b-1dee-4175-bfae-73fad6a3763b"

                { "type", "hidden" },

                { "autocomplete", "off" }

            });

            html.ViewContext.Writer.WriteLine(indexField.ToString(TagRenderMode.SelfClosing));

            return new CollectionItemNamePrefixScope(html.ViewData.TemplateInfo, collectionItemName);

        }

         private class CollectionItemNamePrefixScope : IDisposable

         {

             private readonly TemplateInfo _templateInfo;

             private readonly string _previousPrefix;

             public CollectionItemNamePrefixScope(TemplateInfo templateInfo, string collectionItemName)

             {

                 this._templateInfo = templateInfo;

                 _previousPrefix = templateInfo.HtmlFieldPrefix;

                 templateInfo.HtmlFieldPrefix = collectionItemName;

             }

             public void Dispose()

             {

                 _templateInfo.HtmlFieldPrefix = _previousPrefix;

             }

         }

        /// <summary>

        /// 以FavouriteMovies.Index为键，把Guid字符串存放在上下文中

        /// 如果是添加进入部分视图，就直接生成一个Guid字符串

        /// 如果是更新，为了保持和ModelState的一致，就遍历原先的Guid

        /// </summary>

        /// <param name="collectionIndexFieldName">FavouriteMovies.Index</param>

        /// <returns>返回Guid字符串</returns>

        private static string GetCollectionItemIndex(string collectionIndexFieldName)

        {

            Queue<string> previousIndices = (Queue<string>)HttpContext.Current.Items[collectionIndexFieldName];

            if (previousIndices == null)

            {

                HttpContext.Current.Items[collectionIndexFieldName] = previousIndices = new Queue<string>();

                string previousIndicesValues = HttpContext.Current.Request[collectionIndexFieldName];//HttpContext.Current.Request[FavouriteMovies.Index]

                if (!string.IsNullOrWhiteSpace(previousIndicesValues))

                {

                    foreach (string index in previousIndicesValues.Split(‘,‘))

                    {

                        previousIndices.Enqueue(index);

                    }

                }

            }

            return previousIndices.Count > 0 ? previousIndices.Dequeue() : Guid.NewGuid().ToString();

        }

    }

}