不能定义在MVC定制呈现拉姆达 [英] Can't define a custom renderer lambda in MVC

问题描述

我要定义一个自定义呈现在我的MVC视图拉姆达，我可以用它在部分多次渲染同样的事情。我打算将其存储在视图中的数据。到目前为止，我已经创造了这个扩展方法来存储渲染：

 公共静态类HtmlHelperExtensions
{
   公共静态无效DefineRenderer＆LT;＆的TModel GT;（这与的HtmlHelper LT;的TModel＆GT; HTML，串rendererName，动作渲染器）
   {
      html.ViewData [_渲染+ rendererName] =渲染器;
   }
}
 

我想在我看来来定义渲染器，但它不工作;我想我的语法是关闭的。可能有人告诉我，我在做什么错在这里？我只是希望它渲染所谓当测试段落：

  @ Html.DefineRenderer（AnalysisTableHeader，（）=＆GT; {
    ＆所述p为H.;试验段＆下; / P＆GT;
@}）;
 

解决方案

通过一些灵感来自@ mariozski的评论，我设法得到我想要工作的行为。我用的是 @helper 作为渲染器。我传递给局部模型包含辅助呈现，即的结果。一个 HelperResult 。所以它看起来是这样的：

 公共类AnalysisResponseTableViewModel {
    公共HelperResult HeaderTypeRowRenderer {搞定;组; }
    公开名单＆LT; AnalysisUserResponseViewModel＆GT;回应{搞定;组; }
}
 

然后调用视图调用部分是这样的：

  @helper RenderHeaderTypeRow（）{
    ＆所述; TR类=headerTypeRow＆GT;
        ＆LT; TD＆GT;头型排＆LT; / TD＆GT;
        ＆LT; TD＆GT;去此处＆lt; / TD＆GT;
    ＆LT; / TR＆GT;
}@ Html.Partial（AnalysisResponseTableContentsPartial
    新AnalysisResponseTableViewModel {
        响应= Model.OverallCaseStudyUserResponses，
        HeaderTypeRowRenderer = RenderHeaderTypeRow（）
    }
）
 

和最后部分本身可以呈现头类型行多次这样的：

  @ Html.Raw（Model.HeaderTypeRowRenderer.ToHtmlString（））
@ {布尔reachedSummaryRows = FALSE;}
@foreach（在Model.Responses VAR响应）{
    如果（reachedSummaryRows＆安培;！＆安培;！response.IsPass.HasValue）{
        reachedSummaryRows = TRUE;
        @：@ Html.Raw（Model.HeaderTypeRowRenderer.ToHtmlString（））
    }    //其他表在这里行
}
 

I want to define a custom renderer as a lambda in my MVC view that I can use it in a partial to render the same thing multiple times. I plan to store it in the view data. So far I have created this extension method to store the renderer:

public static class HtmlHelperExtensions
{
   public static void DefineRenderer<TModel>(this HtmlHelper<TModel> html, string rendererName, Action renderer)
   {
      html.ViewData["_Renderer" + rendererName] = renderer;
   }
}

I'm trying to define the renderer in my view, but it isn't working; I assume my syntax is off. Could somebody tell me what I'm doing wrong here? I just want it to render the test paragraph when called:

@Html.DefineRenderer("AnalysisTableHeader", () => {
    <p>test paragraph</p>
@});

解决方案

With some inspiration from @mariozski's comment, I managed to get the behaviour I wanted to work. I use a @helper as the renderer. The model I pass to the partial contains the result of the helper render, ie. a HelperResult. So it looks like this:

public class AnalysisResponseTableViewModel {
    public HelperResult HeaderTypeRowRenderer { get; set; }
    public List<AnalysisUserResponseViewModel> Responses { get; set; }
}

Then, the calling view calls the partial like this:

@helper RenderHeaderTypeRow() {
    <tr class="headerTypeRow">
        <td>Header type row</td>
        <td>Goes here</td>
    </tr>
}

@Html.Partial("AnalysisResponseTableContentsPartial",
    new AnalysisResponseTableViewModel {
        Responses = Model.OverallCaseStudyUserResponses,
        HeaderTypeRowRenderer = RenderHeaderTypeRow()
    }
)

And finally the partial itself can render the 'header type row' multiple times like this:

@Html.Raw(Model.HeaderTypeRowRenderer.ToHtmlString())
@{bool reachedSummaryRows = false;}
@foreach (var response in Model.Responses) {
    if (!reachedSummaryRows && !response.IsPass.HasValue) {
        reachedSummaryRows = true;
        @:@Html.Raw(Model.HeaderTypeRowRenderer.ToHtmlString())
    }

    // other table rows here
}

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