检查是一种特殊形式的字段有效

本文介绍了检查是一种特殊形式的字段有效的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我一直在寻找了一段时间，并没有找到一个解决办法。

我是一个ASP.NET和MVC4 / Razor2新手，所以我主要是编辑默认的项目。

不管怎样，我的问题是，我使用Twitter的引导，我需要添加一个错误在CSS类 DIV 如果下铺设领域是无效的。

到目前为止，我有这样的：

＆LT; D​​IV CLASS =控制组错误＆GT;      @ Html.LabelFor（M = GT; m.Password，新{@class =控制标签}）      ＆LT; D​​IV CLASS =控制＆GT;        @ Html.PasswordFor（M = GT; m.Password）        @ Html.ValidationMessageFor（M = GT; m.Password，空，新的{@class =直列帮助错误}）      ＆LT; / DIV＆GT;    ＆LT; / DIV＆GT;

我应该怎么做才能让剃刀插入错误类中的第一个 DIV 我的片段时，现场是无效的。

更新：我找到了一种方法来做到这一点，但它并不相较于code其余觉得不对劲。有没有更好的办法或者是它的的的方式做到这一点？

＆LT; D​​IV CLASS =控制组@（！（ViewData.ModelState.IsValidField（密码））？错误：），＆GT;

解决方案

这样的：

公共静态类HtmlHelperExtensions{    公共静态MvcHtmlString AddClassIfPropertyInError＆LT;的TModel，TProperty＆GT;（        这与的HtmlHelper LT;的TModel＆GT;的HtmlHelper，        防爆pression＆LT;＆Func键LT;的TModel，TProperty＆GT;＆GT;前pression，        串errorClassName）    {        VAR前pressionText =前pressionHelper.GetEx pressionText（如pression）;        VAR fullHtmlFieldName = htmlHelper.ViewContext.ViewData            .TemplateInfo.GetFullHtmlFieldName（如pressionText）;        VAR状态= htmlHelper.ViewData.ModelState [fullHtmlFieldName]        如果（状态== NULL）        {            返回MvcHtmlString.Empty;        }        如果（state.Errors.Count == 0）        {            返回MvcHtmlString.Empty;        }        返回新MvcHtmlString（errorClassName）;    }}

然后在您的视图：

＆LT; D​​IV CLASS =控制组@ Html.AddClassIfPropertyInError（X =＆GT; x.Email，错误）＆GT;    ＆LT;标签类=控制标签＆GT;电子邮件和LT; /标签＆gt;    ＆LT; D​​IV CLASS =控制＆GT;        ＆LT;输入类型=文本占位符=电子邮件NAME =电子邮件/＆GT;        ＆LT;跨度类=求助在线＆GT; @ Html.ValidationMessageFor（X =＆GT; x.Email）LT; / SPAN＆GT;    ＆LT; / DIV＆GT;＆LT; / DIV＆GT;

I've been searching for a while now and haven't found a solution yet.

I'm an ASP.NET and MVC4/Razor2 newbie, so I'm mostly editing the default project.

Anyway, my issue is that I'm using Twitter Bootstrap and I need to add an error CSS class on a div if the under-laying field is not valid.

So far I have this:

<div class="control-group error"> @Html.LabelFor(m => m.Password, new { @class = "control-label" }) <div class="controls"> @Html.PasswordFor(m => m.Password) @Html.ValidationMessageFor(m => m.Password, null, new { @class = "inline-help error" }) </div> </div>

What should I do to make Razor insert the error class in the first div of my snippet when the field is invalid.

UPDATE: I found a way to do it, but it doesn't feel right in comparison to the rest of the code. Is there a better way or is it the way to do it?

<div class="control-group@((!ViewData.ModelState.IsValidField("Password")) ? " error" : "")">

解决方案

Like this:

public static class HtmlHelperExtensions { public static MvcHtmlString AddClassIfPropertyInError<TModel, TProperty>( this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, string errorClassName) { var expressionText = ExpressionHelper.GetExpressionText(expression); var fullHtmlFieldName = htmlHelper.ViewContext.ViewData .TemplateInfo.GetFullHtmlFieldName(expressionText); var state = htmlHelper.ViewData.ModelState[fullHtmlFieldName]; if (state == null) { return MvcHtmlString.Empty; } if (state.Errors.Count == 0) { return MvcHtmlString.Empty; } return new MvcHtmlString(errorClassName); } }

Then in your view:

<div class="control-group @Html.AddClassIfPropertyInError(x => x.Email, "error")"> <label class="control-label">Email</label> <div class="controls"> <input type="text" placeholder="Email" name="Email" /> <span class="help-inline">@Html.ValidationMessageFor(x => x.Email)</span> </div> </div>