mvc 3 Html.EditorFor添加html属性不起作用

public class MyModel
{
    [Display(Name = "My Property")]
    [UIHint("MyEditorTemplate")]
    public string MyProperty { get; set; }
}

@Html.EditorFor(model => model.MyProperty, new { htmlAttributes = new { @class = "form-control", @placeholder = "Enter some text" } })

<!-- Views/Shared/EditorTemplates/MyEditorTemplate.cshtml -->
@model string
@Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue, new { @class = "form-control", @placeholder = ViewData.ModelMetadata.Watermark })

public ActionResult MyAction()
{
    MyModel model = new MyModel();
    return View(model);
}