C# 向 MVC 项目添加自定义 HTML Helper
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Adding a custom HTML Helper to MVC Project
提问by Code Ratchet
I've been browsing the web trying to find a good example/tutorial detailing how I can create and use my own custom HTML Helpers for my MVC 3 Razor application I found this one which is as follows
我一直在浏览网页，试图找到一个很好的示例/教程，详细说明如何为我的 MVC 3 Razor 应用程序创建和使用我自己的自定义 HTML 帮助程序，我找到了这个，如下所示
Adding your own HtmlHelper in ASP.NET MVC 3
在 ASP.NET MVC 3 中添加您自己的 HtmlHelper
I've created a class (trimmed it down a bit) as so
我已经创建了一个类（将其精简了一点）
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Linq.Expressions;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Html;
namespace MyWebApp
{
public static class ExtensionMethods
{
public static MvcHtmlString StateDropDownListFor<TModel, TValue>
(this HtmlHelper<TModel> html,
Expression<Func<TModel, TValue>> expression)
{
Dictionary<string, string> stateList = new Dictionary<string, string>()
{
{"AL"," Alabama"},
{"AK"," Alaska"},
{"AZ"," Arizona"},
{"AR"," Arkansas"}
};
return html.DropDownListFor(expression,
new SelectList(stateList, "key", "value"));
}
}
}
So far so good,
到现在为止还挺好，
Inside my controller I also added the reference
在我的控制器中，我还添加了引用
using System.Web.Mvc.Html;
Now inside my view i have the following
现在在我看来，我有以下几点
@Html.StateDropDownList(x => x.State)
But I get the following error
但我收到以下错误
System.web.mvc.htmlhelper<system.collections.generic.list<Profile.ProfileImages>> does not contain a definition for StateDropDownList and no extension method StateDropDownList acception a first argument of type system.web.mvc.htmlhelper<System.Collections.Generic.List<Profile.ProfileImages>> could be found(Are you missing a using directive of an assembly reference?)
Could someone please tell me what im doing wrong here.
有人可以告诉我我在这里做错了什么。
采纳答案by Ufuk Hac?o?ullar?
You should include the namespace in your view:
您应该在视图中包含命名空间：
@using MyWebApp
Or you can import this namespace for all of the views from web.config.
或者，您可以为 web.config 中的所有视图导入此命名空间。
<system.web.webPages.razor>
<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="MyWebApp" />
</namespaces>
</pages>
</system.web.webPages.razor>
回答by Michael
I think an easier option would be to do the following: 1. Create a view as usual, place your helpers in that as usual with the mix of code and html as you like. 2. Move the view to the App_Code folder. 3. Get to your helps in all your views as so (Note that _MyHelpers is the name of the view in the App_Code folder):
我认为一个更简单的选择是执行以下操作： 1. 像往常一样创建一个视图，像往常一样将您的助手放入其中，并根据需要混合使用代码和 html。2. 将视图移动到 App_Code 文件夹。3. 在所有视图中获取帮助（请注意，_MyHelpers 是 App_Code 文件夹中视图的名称）：
@_MyHelpers.JQMRadioTrueFalse("Voice Mail on your Home Phone?", "HomePhoneHasAnswerPhone", Model.TrueFalse, t.HomePhoneHasAnswerPhone)
This would be an example of a view in the App_Code folder that is accessed on any view as above:
这将是 App_Code 文件夹中的视图示例，可在上述任何视图上访问：
@helper JQMRadioList(string Legend, string RadioListName, List<Fizz.DomainClasses.GenericClasses.GenericDropDownOption> options, bool Horizontal = false, string CurrentSelection = "")
{
<fieldset data-role="controlgroup" data-mini="true" data-theme="b" @((Horizontal) ? " data-type=\"horizontal\"" : "")>
<legend>@Legend:</legend>
@foreach (var li in options)
{
@JQMRadioListItem(RadioListName, li.TheValue, li.Text, CurrentSelection)
}
</fieldset>
}
