Question

我有一些名称较长的实体，我希望能够使用HTML abbr标记在标签中缩写它们。我使用DataAnnotations为视图模型（或实体类）中的属性提供DisplayName值。

我已经手动执行此操作：

<label class="myClass"><abbr title="@Html.DisplayFor(m => m.Ssn)">SSN</abbr> @Html.EditorFor(m => m.Ssn)</label>

但它变得很痛苦。我想用以下语法设计一个帮助器。

@Html.AbbrLabelFor(m => m.Ssn, "SSN")

和输出：

<label for="Ssn"><abbr title="Social Security Number">SSN</abbr></label>

其中＆＃34;社会安全号码＆＃34;是DisplayName值，helper标记中的第二个参数是缩写文本。所以基本上只是添加第二个参数。

我见过的例子往往会抛弃HtmlAttributes等等，我希望保留这些功能，如：

@Html.AbbrLabelFor(m => m.Ssn, "SSN", new { @class="myClass" })

如何扩展现有的全功能LabelFor来实现它，DfnLabel等？

Answer 1

你的助手需要看起来像

public static MvcHtmlString AbbrLabelFor<TModel, TValue>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TValue>> expression, string abbreviation, object htmlAttributes)    
{
    ModelMetadata metaData = ModelMetadata.FromLambdaExpression(expression, helper.ViewData);
    string name = ExpressionHelper.GetExpressionText(expression)       
    TagBuilder abbr = new TagBuilder("abbr");
    abbr.MergeAttribute("title", metaData.GetDisplayName());
    abbr.InnerHtml = abbreviation;
    TagBuilder label = new TagBuilder("label");
    label.MergeAttribute("for", name);
    label.MergeAttributes(HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes));
    label.InnerHtml = abbr.ToString();

    return MvcHtmlString.Create(label.ToString());
}

编辑（带有重载）

public static MvcHtmlString AbbrLabelFor<TModel, TValue>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TValue>> expression, string abbreviation)
{
    ModelMetadata metaData = ModelMetadata.FromLambdaExpression(expression, helper.ViewData);
    string name = ExpressionHelper.GetExpressionText(expression);
    return AbbrLabelHelper(helper, metaData, name, abbreviation, null);
}

public static MvcHtmlString AbbrLabelFor<TModel, TValue>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TValue>> expression, string abbreviation, object htmlAttributes)
{
    ModelMetadata metaData = ModelMetadata.FromLambdaExpression(expression, helper.ViewData);
    string name = ExpressionHelper.GetExpressionText(expression);
    return AbbrLabelHelper(helper, metaData, name, abbreviation, htmlAttributes);
}

private static MvcHtmlString AbbrLabelHelper(HtmlHelper helper, ModelMetadata metaData, string name, string abbreviation, object htmlAttributes)
{
    TagBuilder abbr = new TagBuilder("abbr");
    abbr.MergeAttribute("title", metaData.GetDisplayName());
    abbr.InnerHtml = abbreviation;
    TagBuilder label = new TagBuilder("label");
    label.MergeAttribute("for", name);
    label.MergeAttributes(HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes));
    label.InnerHtml = abbr.ToString();
    return MvcHtmlString.Create(label.ToString());
}

用于包装HTML标记的LabelFor的助手

1 个答案: