Question

我正在尝试构建一个可以执行此逻辑的帮助程序：

if (ViewData.ModelState[""] != null && ViewData.ModelState[""].Errors.Any())
{
    <div class="note note-danger">
        <h4 class="block">Errors</h4>
        <p>@Html.ValidationSummary()</p>
    </div>
}

需要访问 ViewData 和 Html.ValidationSummary

这些是否需要发送到Helper，Helper可以通过某种基类以某种方式访问它们吗？

我的助手：

public static class ValidationSummaryHelper
{
    public static HtmlString Summary(???)
    { }}

Answer 1

我不知道它在C＃中的语法，但在VB中它看起来像这样：

<Extension>
Public Function AddCustomValidationSummary(htmlHelper As HtmlHelper) As MvcHtmlString
    Dim result As String = String.Empty

    If (htmlHelper.ViewData.ModelState("") Is Nothing) AndAlso (htmlHelper.ViewData.ModelState("").Errors.Any()) Then
        result = "<div class='note note-danger'><h4 class='block'>Errors</h4><p>" & htmlHelper.ValidationSummary().ToString() & "</p></div>"
    End If

    Return New MvcHtmlString(result)
End Function

使用它像：

@Html.AddCustomValidationSummary()

Answer 2

在C＃中相同

public static class ValidationExtensions
{
        public static MvcHtmlString AddCustomValidationSummary(this HtmlHelper htmlHelper)
        {
            string result = "";

            if (htmlHelper.ViewData.ModelState[""] != null && htmlHelper.ViewData.ModelState[""].Errors.Any())
            {
                result = "<div class='note note-danger'><h4 class='block'>Errors</h4><p>" + htmlHelper.ValidationSummary().ToString() + "</p></div>";
            }

            return new MvcHtmlString(result);
        }
}

MVC 4 - 构建访问ViewData的帮助程序

2 个答案: