您可以阅读以下有关编写自定义的文章DataAnnotationsModelMetadataProvider。

这是涉及新引入的IMetadataAware接口的另一种ASP.NET MVC 3ish更多方法。

首先创建一个实现此接口的自定义属性：

public class PlaceHolderAttribute : Attribute, IMetadataAware
{
    private readonly string _placeholder;
    public PlaceHolderAttribute(string placeholder)
    {
        _placeholder = placeholder;
    }

    public void OnMetadataCreated(ModelMetadata metadata)
    {
        metadata.AdditionalValues["placeholder"] = _placeholder;
    }
}

然后用它来装饰模型：

public class MyViewModel
{
    [PlaceHolder("Enter title here")]
    public string Title { get; set; }
}

接下来定义一个控制器：

public class HomeController : Controller
{
    public ActionResult Index()
    {
        return View(new MyViewModel());
    }
}

相应的视图：

@model MyViewModel
@using (Html.BeginForm())
{
    @Html.EditorFor(x => x.Title)
    <input type="submit" value="OK" />
}

最后是编辑器模板（~/Views/Shared/EditorTemplates/string.cshtml）：

@{
    var placeholder = string.Empty;
    if (ViewData.ModelMetadata.AdditionalValues.ContainsKey("placeholder"))
    {
        placeholder = ViewData.ModelMetadata.AdditionalValues["placeholder"] as string;
    }
}
<span>
    @Html.Label(ViewData.ModelMetadata.PropertyName)
    @Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue, new { placeholder = placeholder })
</span>