私はこれらの要件を処理する独自の方法を共有したいと思いました。SessionStateをまったく使用したくなかったし、クライアント側で処理したくもありませんでした。serializeメソッドには、プロジェクトに含めたくないMVC Futureが必要です。
代わりに、モデルのすべてのプロパティを反復処理し、それぞれのカスタム非表示要素を生成するHTMLヘルパーを作成しました。複雑なプロパティの場合、再帰的に実行されます。
フォームでは、「ウィザード」の各ステップで新しいモデルデータとともにコントローラーにポストされます。
これはMVC 5用に作成しました。
using System;
using System.Text;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Web;
using System.Web.Routing;
using System.Web.Mvc;
using System.Web.Mvc.Html;
using System.Reflection;
namespace YourNamespace
{
public static class CHTML
{
public static MvcHtmlString HiddenClassFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression)
{
return HiddenClassFor(html, expression, null);
}
public static MvcHtmlString HiddenClassFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression, object htmlAttributes)
{
ModelMetadata _metaData = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
if (_metaData.Model == null)
return MvcHtmlString.Empty;
RouteValueDictionary _dict = htmlAttributes != null ? new RouteValueDictionary(htmlAttributes) : null;
return MvcHtmlString.Create(HiddenClassFor(html, expression, _metaData, _dict).ToString());
}
private static StringBuilder HiddenClassFor<TModel>(HtmlHelper<TModel> html, LambdaExpression expression, ModelMetadata metaData, IDictionary<string, object> htmlAttributes)
{
StringBuilder _sb = new StringBuilder();
foreach (ModelMetadata _prop in metaData.Properties)
{
Type _type = typeof(Func<,>).MakeGenericType(typeof(TModel), _prop.ModelType);
var _body = Expression.Property(expression.Body, _prop.PropertyName);
LambdaExpression _propExp = Expression.Lambda(_type, _body, expression.Parameters);
if (!_prop.IsComplexType)
{
string _id = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(_propExp));
string _name = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(_propExp));
object _value = _prop.Model;
_sb.Append(MinHiddenFor(_id, _name, _value, htmlAttributes));
}
else
{
if (_prop.ModelType.IsArray)
_sb.Append(HiddenArrayFor(html, _propExp, _prop, htmlAttributes));
else if (_prop.ModelType.IsClass)
_sb.Append(HiddenClassFor(html, _propExp, _prop, htmlAttributes));
else
throw new Exception(string.Format("Cannot handle complex property, {0}, of type, {1}.", _prop.PropertyName, _prop.ModelType));
}
}
return _sb;
}
public static MvcHtmlString HiddenArrayFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression)
{
return HiddenArrayFor(html, expression, null);
}
public static MvcHtmlString HiddenArrayFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression, object htmlAttributes)
{
ModelMetadata _metaData = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
if (_metaData.Model == null)
return MvcHtmlString.Empty;
RouteValueDictionary _dict = htmlAttributes != null ? new RouteValueDictionary(htmlAttributes) : null;
return MvcHtmlString.Create(HiddenArrayFor(html, expression, _metaData, _dict).ToString());
}
private static StringBuilder HiddenArrayFor<TModel>(HtmlHelper<TModel> html, LambdaExpression expression, ModelMetadata metaData, IDictionary<string, object> htmlAttributes)
{
Type _eleType = metaData.ModelType.GetElementType();
Type _type = typeof(Func<,>).MakeGenericType(typeof(TModel), _eleType);
object[] _array = (object[])metaData.Model;
StringBuilder _sb = new StringBuilder();
for (int i = 0; i < _array.Length; i++)
{
var _body = Expression.ArrayIndex(expression.Body, Expression.Constant(i));
LambdaExpression _arrayExp = Expression.Lambda(_type, _body, expression.Parameters);
ModelMetadata _valueMeta = ModelMetadata.FromLambdaExpression((dynamic)_arrayExp, html.ViewData);
if (_eleType.IsClass)
{
_sb.Append(HiddenClassFor(html, _arrayExp, _valueMeta, htmlAttributes));
}
else
{
string _id = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(_arrayExp));
string _name = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(_arrayExp));
object _value = _valueMeta.Model;
_sb.Append(MinHiddenFor(_id, _name, _value, htmlAttributes));
}
}
return _sb;
}
public static MvcHtmlString MinHiddenFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression)
{
return MinHiddenFor(html, expression, null);
}
public static MvcHtmlString MinHiddenFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression, object htmlAttributes)
{
string _id = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(expression));
string _name = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression));
object _value = ModelMetadata.FromLambdaExpression(expression, html.ViewData).Model;
RouteValueDictionary _dict = htmlAttributes != null ? new RouteValueDictionary(htmlAttributes) : null;
return MinHiddenFor(_id, _name, _value, _dict);
}
public static MvcHtmlString MinHiddenFor(string id, string name, object value, IDictionary<string, object> htmlAttributes)
{
TagBuilder _input = new TagBuilder("input");
_input.Attributes.Add("id", id);
_input.Attributes.Add("name", name);
_input.Attributes.Add("type", "hidden");
if (value != null)
{
_input.Attributes.Add("value", value.ToString());
}
if (htmlAttributes != null)
{
foreach (KeyValuePair<string, object> _pair in htmlAttributes)
{
_input.MergeAttribute(_pair.Key, _pair.Value.ToString(), true);
}
}
return new MvcHtmlString(_input.ToString(TagRenderMode.SelfClosing));
}
}
}
これで、「ウィザード」のすべてのステップで、同じ基本モデルを使用して、ラムダ式を使用して「ステップ1,2,3」モデルプロパティを@ Html.HiddenClassForヘルパーに渡すことができます。
必要に応じて、各ステップで[戻る]ボタンを使用することもできます。formaction属性を使用してコントローラのStepNBackアクションに投稿するフォームに戻るボタンを置くだけです。以下の例には含まれていませんが、単なるアイデアです。
とにかくここに基本的な例があります：
こちらがモデルです
public class WizardModel
{
// you can store additional properties for your "wizard" / parent model here
// these properties can be saved between pages by storing them in the form using @Html.MinHiddenFor(m => m.WizardID)
public int? WizardID { get; set; }
public string WizardType { get; set; }
[Required]
public Step1 Step1 { get; set; }
[Required]
public Step2 Step2 { get; set; }
[Required]
public Step3 Step3 { get; set; }
// if you want to use the same model / view / controller for EDITING existing data as well as submitting NEW data here is an example of how to handle it
public bool IsNew
{
get
{
return WizardID.HasValue;
}
}
}
public class Step1
{
[Required]
[MaxLength(32)]
[Display(Name = "First Name")]
public string FirstName { get; set; }
[Required]
[MaxLength(32)]
[Display(Name = "Last Name")]
public string LastName { get; set; }
}
public class Step2
{
[Required]
[MaxLength(512)]
[Display(Name = "Biography")]
public string Biography { get; set; }
}
public class Step3
{
// lets have an array of strings here to shake things up
[Required]
[Display(Name = "Your Favorite Foods")]
public string[] FavoriteFoods { get; set; }
}
こちらがコントローラーです
public class WizardController : Controller
{
[HttpGet]
[Route("wizard/new")]
public ActionResult New()
{
WizardModel _model = new WizardModel()
{
WizardID = null,
WizardType = "UserInfo"
};
return View("Step1", _model);
}
[HttpGet]
[Route("wizard/edit/{wizardID:int}")]
public ActionResult Edit(int wizardID)
{
WizardModel _model = database.GetData(wizardID);
return View("Step1", _model);
}
[HttpPost]
[Route("wizard/step1")]
public ActionResult Step1(WizardModel model)
{
// just check if the values in the step1 model are valid
// shouldn't use ModelState.IsValid here because that would check step2 & step3.
// which isn't entered yet
if (ModelState.IsValidField("Step1"))
{
return View("Step2", model);
}
return View("Step1", model);
}
[HttpPost]
[Route("wizard/step2")]
public ActionResult Step2(WizardModel model)
{
if (ModelState.IsValidField("Step2"))
{
return View("Step3", model);
}
return View("Step2", model);
}
[HttpPost]
[Route("wizard/step3")]
public ActionResult Step3(WizardModel model)
{
// all of the data for the wizard model is complete.
// so now we check the entire model state
if (ModelState.IsValid)
{
// validation succeeded. save the data from the model.
// the model.IsNew is just if you want users to be able to
// edit their existing data.
if (model.IsNew)
database.NewData(model);
else
database.EditData(model);
return RedirectToAction("Success");
}
return View("Step3", model);
}
}
こちらがあなたのビューです
ステップ1
@model WizardModel
@{
ViewBag.Title = "Step 1";
}
@using (Html.BeginForm("Step1", "Wizard", FormMethod.Post))
{
@Html.MinHiddenFor(m => m.WizardID)
@Html.MinHiddenFor(m => m.WizardType)
@Html.LabelFor(m => m.Step1.FirstName)
@Html.TextBoxFor(m => m.Step1.FirstName)
@Html.LabelFor(m => m.Step1.LastName)
@Html.TextBoxFor(m => m.Step1.LastName)
<button type="submit">Submit</button>
}
ステップ2
@model WizardModel
@{
ViewBag.Title = "Step 2";
}
@using (Html.BeginForm("Step2", "Wizard", FormMethod.Post))
{
@Html.MinHiddenFor(m => m.WizardID)
@Html.MinHiddenFor(m => m.WizardType)
@Html.HiddenClassFor(m => m.Step1)
@Html.LabelFor(m => m.Step2.Biography)
@Html.TextAreaFor(m => m.Step2.Biography)
<button type="submit">Submit</button>
}
ステップ3
@model WizardModel
@{
ViewBag.Title = "Step 3";
}
@using (Html.BeginForm("Step3", "Wizard", FormMethod.Post))
{
@Html.MinHiddenFor(m => m.WizardID)
@Html.MinHiddenFor(m => m.WizardType)
@Html.HiddenClassFor(m => m.Step1)
@Html.HiddenClassFor(m => m.Step2)
@Html.LabelFor(m => m.Step3.FavoriteFoods)
@Html.ListBoxFor(m => m.Step3.FavoriteFoods,
new SelectListItem[]
{
new SelectListItem() { Value = "Pizza", Text = "Pizza" },
new SelectListItem() { Value = "Sandwiches", Text = "Sandwiches" },
new SelectListItem() { Value = "Burgers", Text = "Burgers" },
});
<button type="submit">Submit</button>
}
