Binding conflict between a property named Title in my Model and View.Title in my View (in MVC)
My Model contains a property named Title
, and in my Create
view I set the page title using ViewBag.Title
.
This creates the following problem: the form generated by Html.Editor
will display the text from ViewBag.Title
, instead of the model's Title
value.
The only workaround I have found is first calling Html.Editor
, and then setting the View.Title
.
Does anyone have a better solution?
Edit 1: I am using MVC 3.
Edit 2: This is my DisplayTemplates/Object.cshtml
:
@model dynamic
@using Iconum.VS10CS040.Library.Web.MVC3.Helpers
@if (ViewData.TemplateInfo.TemplateDepth > 1) {
<span class="editor-object simple">@ViewData.ModelMetadata.SimpleDisplayText</span>
} else {
foreach (var prop in ViewData.ModelMetadata.Properties.Where(
pm =>
pm.ShowForEdit
&& !ViewData.TemplateInfo.Visited(pm)
&& pm.ModelType != typeof(System.Data.EntityState)
&& !pm.IsComplexType
)
)
{
if (prop.HideSurroundingHtml) {
<text>@Html.Editor(prop.PropertyName)</text>
} else {
string css = "";
if (prop.Model != null && prop.Model.GetType() != null)
{
css += " " + prop.Model.GetType().ToString().ToLower().Replace('.', '-');
}
if (prop.DataTypeName != null)
{
css += " " + prop.DataTypeName.ToLower();
}
if (prop.IsRequired && prop.ModelType.FullName != "System.Boolean")
{
css += " required";
}
<div class="editor-container @css">
<div class="editor-label">
@if (!String.IsNullOrEmpty(Html.Label(prop.PropertyName).ToHtmlString()))
{
// Use LabelWithForThatMatchesTheIdOfTheInput instead of Label because of a bug (fixed in MVC 3)
@Html.LabelWithForThatMatchesTheIdOfTheInput(prop.PropertyName)
}
@if (prop.IsRequired && prop.ModelType.FullName != "System.Boolean")
{
@Html.Raw(" <span class=\"required\">*<span>");
}
</div>
<div class="editor-field">
@* This the line that causes my problem *@
开发者_C百科 @Html.Editor(prop.PropertyName)
@Html.ValidationMessage(prop.PropertyName)
</div>
</div>
}
} //foreach
// Loop though all items in the Model with an TemplateHint (UIHint)
foreach (var prop in ViewData.ModelMetadata.Properties.Where(
pm => pm.ShowForEdit
&& !ViewData.TemplateInfo.Visited(pm)
&& pm.ModelType != typeof(System.Data.EntityState)
&& !pm.IsComplexType
&& pm.TemplateHint != null
&& (
pm.TemplateHint == "jWYSIWYG0093"
||
pm.TemplateHint == "jQueryUIDatepicker"
||
pm.TemplateHint == "CKEditor"
)
)
)
{
// TODO: check for duplicate js file includes
@Html.Editor(prop.PropertyName, prop.TemplateHint + "-Script")
}
}
I would recommend using EditorFor
instead of Editor
.
Html.EditorFor(x => x.Title)
instead of:
Html.Editor("Title")
This way not only that the view takes advantage of your view model but it behaves as expected in this case.
Example with ASP.NET MVC 3.0 RTM (Razor):
Model:
public class MyViewModel
{
public string Title { get; set; }
}
Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
ViewBag.Title = "ViewBag title";
ViewData["Title"] = "ViewData title";
var model = new MyViewModel
{
Title = "Model title"
};
return View(model);
}
}
View:
@model AppName.Models.MyViewModel
@{
ViewBag.Title = "Home Page";
}
@Html.EditorFor(x => x.Title)
@{
ViewBag.Title = "Some other title";
}
So no matter how much we try to abuse here the editor template uses the correct model title (which is not the case if we used Html.Editor("Title")
).
As suggested by the other answers, using EditorFor
instead of Editor
seems to work around the problem. However, using EditorFor
requires knowledge of the model type and property type at compile-time, which isn't the case for Object.cshtml
.
You can still do this by building up and calling the correct generically-constructed EditorFor
method using reflection. The code to do this is really messy, so here are some re-usable extension methods to do it for you.
Use them like this in Object.cshtml
where prop
is an instance of ModelMetadata
like in the question:
@Html.DisplayFor(prop)
@Html.LabelFor(prop)
@Html.EditorFor(prop)
@Html.ValidationMessageFor(prop)
Here are the extension methods:
using System;
using System.Linq.Expressions;
using System.Reflection;
using System.Web.Mvc;
using System.Web.Mvc.Html;
using System.Web.Routing;
namespace ASP
{
public static class NonStronglyTypedStronglyTypedHtmlHelpers
{
public static MvcHtmlString DisplayFor<TModel>(this HtmlHelper<TModel> html, ModelMetadata prop)
{
return StronglyTypedHelper(html, h => h.DisplayFor, prop);
}
public static MvcHtmlString EditorFor<TModel>(this HtmlHelper<TModel> html, ModelMetadata prop)
{
return StronglyTypedHelper(html, h => h.EditorFor, prop);
}
public static MvcHtmlString LabelFor<TModel>(this HtmlHelper<TModel> html, ModelMetadata prop)
{
return StronglyTypedHelper(html, h => h.LabelFor, prop);
}
public static MvcHtmlString ValidationMessageFor<TModel>(this HtmlHelper<TModel> html, ModelMetadata prop)
{
return StronglyTypedHelper(html, h => h.ValidationMessageFor, prop);
}
private static MvcHtmlString StronglyTypedHelper(HtmlHelper html, Func<HtmlHelper<object>, GenericHelper<object>> accessMethod, ModelMetadata prop)
{
var constructedMethod = MakeStronglyTypedHelper(html, accessMethod, prop);
var genericPropertyExpression = MakePropertyExpression(prop);
var typedHtmlHelper = MakeStronglyTypedHtmlHelper(html, prop.ContainerType);
return (MvcHtmlString)constructedMethod.Invoke(null, new object[] { typedHtmlHelper, genericPropertyExpression });
}
private static MethodInfo MakeStronglyTypedHelper(HtmlHelper html, Func<HtmlHelper<object>, GenericHelper<object>> accessMethod, ModelMetadata prop)
{
var objectTypeHelper = new HtmlHelper<object>(html.ViewContext, html.ViewDataContainer, html.RouteCollection);
var runMethod = accessMethod(objectTypeHelper);
var constructedMehtod = runMethod.Method;
var genericHelperDefinition = constructedMehtod.GetGenericMethodDefinition();
return genericHelperDefinition.MakeGenericMethod(prop.ContainerType, prop.ModelType);
}
private static object MakeStronglyTypedHtmlHelper(HtmlHelper html, Type type)
{
var genericTypeDefinition = typeof(HtmlHelper<>);
var constructedType = genericTypeDefinition.MakeGenericType(type);
var constructor = constructedType.GetConstructor(new[] { typeof(ViewContext), typeof(IViewDataContainer), typeof(RouteCollection) });
return constructor.Invoke(new object[] { html.ViewContext, html.ViewDataContainer, html.RouteCollection });
}
private static LambdaExpression MakePropertyExpression(ModelMetadata prop)
{
var propertyInfo = prop.ContainerType.GetProperty(prop.PropertyName);
var expressionParameter = Expression.Parameter(prop.ContainerType);
var propertyExpression = Expression.MakeMemberAccess(expressionParameter, propertyInfo);
return Expression.Lambda(propertyExpression, expressionParameter);
}
private delegate MvcHtmlString GenericHelper<TModel>(Expression<Func<TModel, object>> expression);
}
}
I found partial solution myself.
Just use:
@Html.EditorForModel()
instead of:
@foreach (var property in Model.GetMetadata().Properties)
{
<div class="editor-label">
@Html.Label(property.PropertyName)
</div>
<div class="editor-field">
@Html.Editor(property.PropertyName)
@Html.ValidationMessage(property.PropertyName)
</div>
}
Html.EditorForModel() method return same results, but without described problem.
I solve same problem. Use this syntax instead Html.Editor
@(Html.EditorFor(p => property.Model))
精彩评论