MVC htmlAttributes and additionalViewData

@Html.TextBoxFor(m => m.UserName, new { title = "ABC" })

// 输出结果为

<input data-val="true" data-val-required="The User name field is required." id="UserName" name="UserName" title="ABC" type="text" value="" />

@Html.EditorFor(m => m.UserName, new { title = "ABC" })

// 输出结果为

<input class="text-box single-line" data-val="true" data-val-required="The User name field is required." id="UserName" name="UserName" type="text" value="" />

很显然，第一个例子可以输出title属性，但第二个例子没有输出title属性。

原因是第一个例子的第二个参数为htmlAttributes，第二个例子中第二个参数为additionalViewData。

解决方案：

将htmlAttributes作为additionalViewData中的一个参数使用。如下：

@Html.EditorFor(model => model.EmailAddress,

                new { htmlAttributes = new { @class = "span4",

                                             maxlength = ,

                                             required = true,

                                             placeholder = "Email Address",

                                             title = "A valid email address is required (i.e. [email protected])" } })

public static IDictionary<string, object> MergeHtmlAttributes<TModel>(this HtmlHelper<TModel> htmlHelper, object htmlAttributes)

{

    var attributes = htmlHelper.ViewData.ContainsKey("htmlAttributes")

                            ? HtmlHelper.AnonymousObjectToHtmlAttributes(htmlHelper.ViewData["htmlAttributes"])

                            : new RouteValueDictionary();

    if (htmlAttributes != null)

    {

        foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(htmlAttributes))

        {

            var key = property.Name.Replace('_', '-');

            if (!attributes.ContainsKey(key))

            {

                attributes.Add(key, property.GetValue(htmlAttributes));

            }

        }

    }

    return attributes;

}