MVC4 URLHelper工作，但的HtmlHelper不是。我在做什么错

问题描述

在一<一href=\"http://stackoverflow.com/questions/14771615/mvc-helpers-working-inline-but-not-in-app-$c$c/14771649#comment20683028_14771649\">$p$pvious帖子我问一个关于入门佣工问题。我成功了，但是当我试图用该技术1.要编写基于Html.RenderAction不同的帮手，和2。要在自己的自定义帮助我得到的错误，一旦他们被出口到APP_ code通过。

In a previous post I asked a question about getting started with helpers. I was successful but when I tried to use the technique 1. To write a different helper based on Html.RenderAction, and 2. To pass in my own custom helper I got errors once they were exported to App_Code.

再次强调的是，他们的工作内联，而不是在出口APP_ code。

Again, to emphasise, they work inline, but not when exported to App_Code.

下面是原来的code：

Here is the original code:

我的许多code的部分只有以下内容：

Many parts of my code have only the following:

    <section class="Box">
        @{ Html.RenderAction("PageOne"); }
    </section>

其他许多地方都有这样的：

Many other parts have this:

@if (@Model.PageTwo)
{
    <section class="Box">
        @{ Html.RenderAction("PageTwo"); }
    </section>
}

所以，我的第一步是把解压出来到内联帮手可能在我所有的code块的使用上面的以下内容：

So my first step was to extract out into an inline helper the following which could be used in all of my code blocks above:

@helper Item(HtmlHelper html, string action, string htmlClass)
{
    <section class="@htmlClass">
        @{ html.RenderAction(action); }
    </section>
}

上面的助手让我来代替，看起来像第一个code段上面这条线的所有code块：

The helper above allows me to replace all the code blocks that look like the first code segment above with this line:

@Item(Html, "PageOne", "Box")

然后我接着写第二个帮手，看起来是这样的：

Then I went on to write the second helper which looks like this:

@helper Item(HtmlHelper html, string action, string htmlClass, bool test)
{
    if (test)
    {
        @Item(html, action, htmlClass)
    }
}

这个助手可以让我来代替，看起来像第二code段上面这条线的所有code块：

This helper allows me to replace all the code blocks that look like the second code segment above with this line:

@Item(Html, "PageTwo", "Box", @Model.ShowThisTorF)

我的主要问题是再次，这个工作内联，那么为什么不当我把它消除APP_ code。

My main question once again is, this works inline, so why not when I remove it to App_Code.

有一次，我将它移动到APP_ code我得到以下错误：
第一个问题是关于增加一个使用引用（因为是的HtmlHelper暧昧），而我加code的以下行：

Once I move it to App_Code I get the following errors:The first problem is regarding adding a using reference (because HtmlHelper is ambiguous) to which I add the following line of code:

 @using HtmlHelper=System.Web.Mvc.HtmlHelper

这将删除第一个错误，但后来我得到另一个错误：

This removes the first error but then I get another error:

System.Web.Mvc.HtmlHelper不包含一个定义
  的RenderAction'，没有扩展方法'的RenderAction接受
  类型'System.Web.Mvc.HtmlHelper'的第一个参数可以发现（有
  你缺少using指令或程序集引用？）

我也试过其他的参考，但没有结果：

I have also tried the other reference but with no result:

 @using HtmlHelper=System.Web.WebPages.Html.HtmlHelper

这是我遇到的另一个问题是，我不认为一旦我得到的第一个工作的第二块将工作。尽管它工作得很好直列。

Another problem that I am having is that I don't think the second block will work once I get the first one working. Even though it worked fine inline.

另外，我知道它很明显，但如果我不说这里了，有人会问在他们的答案。当我把它输出到文件APP_ code，根据需要使code的一条线肿块看起来像我确实添加文件名preFIX：

Also, I know its obvious, but if I don't say it here, someone will ask it in their answer. When I moved it out to the file App_Code, I did indeed add the file name prefix as required so the one line lumps of code looked something like:

@Helpers.Item(Html, "PageOne", "Box")
@Helpers.Item(Html, "PageTwo", "Box", @Model.ShowThisTorF)

感谢任何帮助。

推荐答案

正确的HtmlHelper 里面助手在APP_ code目录是 System.Web.Mvc.HtmlHelper 。

The correct HtmlHelper inside helpers in the App_Code directory is the System.Web.Mvc.HtmlHelper.

由于的RenderAction 是你需要添加一个扩展方法使用为在声明这是命名空间 @using System.Web.Mvc.Html

Because RenderAction is an extension method you need to add a using for the namespace where it is declared which is @using System.Web.Mvc.Html

所以这个应该工作假设你的文件被命名为 Helpers.cshtml ，并在APP_ $ C $目录C：

So this should work assuming your file is named Helpers.cshtml and in the App_Code directory:

@using HtmlHelper=System.Web.Mvc.HtmlHelper
@using System.Web.Mvc.Html

@helper Item(HtmlHelper html, string action, string htmlClass)
{
    <section class="@htmlClass">
        @{ html.RenderAction(action); }
    </section>
}
@helper Item(HtmlHelper html, string action, string htmlClass, bool test)
{
    if (test)
    {
        @Item(html, action, htmlClass)
    }
}

和用法：

@Helpers.Item(Html, "PageOne", "Box")
@Helpers.Item(Html, "PageTwo", "Box", @Model.ShowThisTorF)

这篇关于MVC4 URLHelper工作，但的HtmlHelper不是。我在做什么错的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！