功能需求描述
Q:在实际的开发中,经常会遇到一个模型中包含有多个条目的表单。如何将数据提交到后台?
A: 以数组的形式提交到后台就Ok了(真的那么简单么,如果再嵌套一层呢?)
A2:拆分多个模型,映射就没啥问题了。但......有点麻烦啊~~
接下来说说如何将下面的模型提交到后台
/// <summary>/// 计划模型/// </summary>public class PlanModel{public int Id{ get; set; }/// <summary>/// 计划名称/// </summary>public string PlanName { get; set; }/// <summary>/// 描述/// </summary>public string Remark { get; set; }/// <summary>/// 方案集合/// </summary>public List<CaseModel> Cases { get; set; }}/// <summary>/// 方案模型/// </summary>public class CaseModel{public int Id{ get; set; }/// <summary>/// 标题/// </summary>public string Title { get; set; }/// <summary>/// 描述/// </summary>public string Description { get; set; }/// <summary>/// 作者/// </summary>public string Author { get; set; }}
根据此模型,编辑的页面会如下图所示,一些基本信息加上可增可减的条目
实现效果
如何实现这个功能(asp.net mvc)
- 新建视图页面(略)
条目的显示增加删除
控制器代码
public class HomeController : Controller{[HttpGet]public ActionResult Index(){var model = new PlanModel() {};return View(model);}public ActionResult CaseRow(){return View("_CaseRow", new CaseModel());}[HttpPost]public ActionResult Form(PlanModel model){return Json(model);}}
编辑页条目显示代码
<div class="form-group"><label class="col-sm-3 control-label">计划方案:</label><div class="col-sm-7 "><table class="table table-bordered table-condensed"><thead><tr class="text-center"><th class="text-center">方案名称</th><th class="text-center">方案作者</th><th class="text-left">方案描述</th><th class="text-center" width="100"><span>操作</span><span title="添加方案" id="add_case" class="glyphicon glyphicon-plus"></span></th></tr></thead><tbody id="case_list">@if (Model.Cases != null){foreach (var item in Model.Cases){Html.RenderPartial("_CaseRow", item);}}</tbody></table></div></div>
页面增加/删按钮js代码 + 验证
<script src="~/Scripts/jquery.validate.min.js"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>
<script type="text/javascript">$(function () {$("#case_list").delegate(".del_tr", "click", function () {$(this).closest("tr").remove();});$("#add_case").click(function () {//ajax请求返回新增方案视图代码$.get('@Url.Action("CaseRow")', function (data) {$("#case_list").append(data);//重置验证模型$("form").removeData("validator").removeData("unobtrusiveValidation");$.validator.unobtrusive.parse($("form"));});});});
</script>
_CaseRow.cshtml分部视图代码
若要以集合/数组的形式提交到后台,须以name[]的格式提交,所以我能想到的就是这样去写(这种方案不可取!!)
但是这样写的话且不说太麻烦,验证也不行,一不小心也就写错了。所以这种方案并不可取
@{ Layout = null;KeyValuePair<string, string> keyValuePair = new KeyValuePair<string, string>("Cases", Guid.NewGuid().ToString("N"));var prefix = keyValuePair.Key+"["+keyValuePair.Value+"].";
}
@model MvcDemo.Models.CaseModel
<tr><td><input type="hidden" name="@(keyValuePair.Key+".index")" value="@keyValuePair.Value"/><input type="hidden" class="form-control" name="@(prefix)Id" value="@Model.Id" /><input type="text" class="form-control" name="@(prefix)Title" value="@Model.Title" /></td><td>@Html.TextBox(prefix+nameof(Model.Author),Model.Author, new { @class = "form-control" })</td><td>@Html.TextBox(prefix + nameof(Model.Description), Model.Description, new { @class = "form-control" })</td><td class="text-center"><span class="del_tr glyphicon glyphicon-remove-circle"></span></td>
</tr>
而后发现大神写的一个HtmlPrefixScopeExtensions扩展类,可自动生成的表单前缀标识,使用方便,也能够使用验证
只需将表单包裹在@using (Html.BeginCollectionItem("子集合的属性名称")){}
中即可,文末分享
@{ Layout = null;
}
@model MvcDemo.Models.CaseModel
@using MvcDemo.Extensions
<tr>@using (Html.BeginCollectionItem("Cases")){<td>@Html.HiddenFor(e => e.Id)@Html.TextBoxFor(e => e.Title, new { @class = "form-control" })@Html.ValidationMessageFor(e => e.Title)</td><td>@Html.TextBoxFor(e => e.Author, new { @class = "form-control" })</td><td>@Html.TextBoxFor(e => e.Description, new { @class = "form-control" })</td><td class="text-center"><span class="del_tr glyphicon glyphicon-remove-circle"></span></td>}
</tr>
然后提交表单可以发现格式如下,并能取到数据
MvcDemo.Extensions命名空间下的HtmlPrefixScopeExtensions扩展类
命名空间自行引用
- asp.net mvc版本
public static class HtmlPrefixScopeExtensions{private const string IdsToReuseKey = "__htmlPrefixScopeExtensions_IdsToReuse_";/// <summary>/// /// </summary>/// <param name="html"></param>/// <param name="collectionName"></param>/// <param name="createDummyForm">是否使用虚拟表单,为了解决上下文中不存在表单,无法生成验证信息</param>/// <returns></returns>public static IDisposable BeginCollectionItem(this HtmlHelper html, string collectionName,bool createDummyForm = false, bool clientValidationEnabled = false){if (clientValidationEnabled == true)html.ViewContext.ClientValidationEnabled = true;if (createDummyForm == true){if (html.ViewContext != null && html.ViewContext.FormContext == null){var dummyFormContext = new FormContext();html.ViewContext.FormContext = dummyFormContext;}}return BeginCollectionItem(html, collectionName, html.ViewContext.Writer);}private static IDisposable BeginCollectionItem(this HtmlHelper html, string collectionName, TextWriter writer){var idsToReuse = GetIdsToReuse(html.ViewContext.HttpContext, collectionName);var itemIndex = idsToReuse.Count > 0 ? idsToReuse.Dequeue() : Guid.NewGuid().GetHashCode().ToString("x");writer.WriteLine("<input type=\"hidden\" name=\"{0}.index\" autocomplete=\"off\" value=\"{1}\" />",collectionName, html.Encode(itemIndex));return BeginHtmlFieldPrefixScope(html, string.Format("{0}[{1}]", collectionName, itemIndex));}private static IDisposable BeginHtmlFieldPrefixScope(this HtmlHelper html, string htmlFieldPrefix){return new HtmlFieldPrefixScope(html.ViewData.TemplateInfo, htmlFieldPrefix);}private static Queue<string> GetIdsToReuse(HttpContextBase httpContext, string collectionName){var key = IdsToReuseKey + collectionName;var queue = (Queue<string>)httpContext.Items[key];if (queue == null){httpContext.Items[key] = queue = new Queue<string>();var previouslyUsedIds = httpContext.Request[collectionName + ".index"];if (!string.IsNullOrEmpty(previouslyUsedIds))foreach (var previouslyUsedId in previouslyUsedIds.Split(','))queue.Enqueue(previouslyUsedId);}return queue;}internal class HtmlFieldPrefixScope : IDisposable{internal readonly TemplateInfo TemplateInfo;internal readonly string PreviousHtmlFieldPrefix;public HtmlFieldPrefixScope(TemplateInfo templateInfo, string htmlFieldPrefix){TemplateInfo = templateInfo;PreviousHtmlFieldPrefix = TemplateInfo.HtmlFieldPrefix;TemplateInfo.HtmlFieldPrefix = htmlFieldPrefix;}public void Dispose(){TemplateInfo.HtmlFieldPrefix = PreviousHtmlFieldPrefix;}}}
- asp.net core版本
public static class HtmlPrefixScopeExtensions{private const string IdsToReuseKey = "__htmlPrefixScopeExtensions_IdsToReuse_";public static IDisposable BeginCollectionItem(this IHtmlHelper html, string collectionName){return BeginCollectionItem(html, collectionName, html.ViewContext.Writer);}private static IDisposable BeginCollectionItem(this IHtmlHelper html, string collectionName, TextWriter writer){if (html.ViewData["ContainerPrefix"] != null)collectionName = string.Concat(html.ViewData["ContainerPrefix"], ".", collectionName);var idsToReuse = GetIdsToReuse(html.ViewContext.HttpContext, collectionName);var itemIndex = idsToReuse.Count > 0 ? idsToReuse.Dequeue() : Guid.NewGuid().ToString();string htmlFieldPrefix = $"{collectionName}[{itemIndex}]";html.ViewData["ContainerPrefix"] = htmlFieldPrefix;/* * html.Name(); has been removed* because of incorrect naming of collection items* e.g.* let collectionName = "Collection"* the first item's name was Collection[0].Collection[<GUID>]* instead of Collection[<GUID>]*/string indexInputName = $"{collectionName}.index";// autocomplete="off" is needed to work around a very annoying Chrome behaviour// whereby it reuses old values after the user clicks "Back", which causes the// xyz.index and xyz[...] values to get out of sync.writer.WriteLine($@"<input type=""hidden"" name=""{indexInputName}"" autocomplete=""off"" value=""{html.Encode(itemIndex)}"" />");return BeginHtmlFieldPrefixScope(html, htmlFieldPrefix);}private static IDisposable BeginHtmlFieldPrefixScope(this IHtmlHelper html, string htmlFieldPrefix){return new HtmlFieldPrefixScope(html.ViewData.TemplateInfo, htmlFieldPrefix);}private static Queue<string> GetIdsToReuse(HttpContext httpContext, string collectionName){// We need to use the same sequence of IDs following a server-side validation failure,// otherwise the framework won't render the validation error messages next to each item.var key = IdsToReuseKey + collectionName;var queue = (Queue<string>)httpContext.Items[key];if (queue == null){httpContext.Items[key] = queue = new Queue<string>();if (httpContext.Request.Method == "POST" && httpContext.Request.HasFormContentType){StringValues previouslyUsedIds = httpContext.Request.Form[collectionName + ".index"];if (!string.IsNullOrEmpty(previouslyUsedIds))foreach (var previouslyUsedId in previouslyUsedIds)queue.Enqueue(previouslyUsedId);}}return queue;}internal class HtmlFieldPrefixScope : IDisposable{internal readonly TemplateInfo TemplateInfo;internal readonly string PreviousHtmlFieldPrefix;public HtmlFieldPrefixScope(TemplateInfo templateInfo, string htmlFieldPrefix){TemplateInfo = templateInfo;PreviousHtmlFieldPrefix = TemplateInfo.HtmlFieldPrefix;TemplateInfo.HtmlFieldPrefix = htmlFieldPrefix;}public void Dispose(){TemplateInfo.HtmlFieldPrefix = PreviousHtmlFieldPrefix;}}}
命名空间自行引用~~
End
完整源码:https://coding.net/u/yimocoding/p/WeDemo/git/tree/MvcFormExt/MvcFormExt/MvcDemo