你会得到一个空水印的原因是，在你的情况下（即不使用模板）的的ViewData ​​ em>的实际上是指 myFormModel （不是 myFormModel.firstFieldValue ）;你基本上是检索您的视图模型的水印。由于模型不能有水印（ [显示] 不能应用于类） ViewData.ModelMetadata.Watermark 永远是空的观点。

The reason you get an empty watermark is that in your case (i.e. not using templates) ViewData actually refers to myFormModel (not myFormModel.firstFieldValue); you are essentially retrieving the watermark of your view model. Since models can't have watermarks ([Display] can't be applied to classes) ViewData.ModelMetadata.Watermark will always be empty for views.

据我所看到的，在这里你唯一的选择（如果你不想使用模板）做水印嵌入：

As far as I can see, your only option here (if you don't want to use templates) is doing the watermark inline:

@Html.TextBoxFor(x => x.firstFieldValue, new { @class = "myInputStyle", placeholder = "Your watermark text here" })

顺便说一句，如果要使用模板，您需要使用模板助手 @ Html.EditorFor（）和 @ Html.DisplayFor （）。 @ Html.TextBoxFor（）仅仅是强类型 @ Html.TextBox（）版本。它不是模板

By the way, if want to use templates, you need to use the templated helpers @Html.EditorFor() and @Html.DisplayFor(). @Html.TextBoxFor() is just the strongly-typed version of @Html.TextBox(). It is not templated.