Question

I’m trying to apply a Style to the Editor for an element, but I can’t make it work; what am I doing wrong?

@Html.EditorFor(model => model.ClienteNuevo)
@Html.ValidationMessageFor(model => model.ClienteNuevo,"" ,new Dictionary<string,     string> { { "style", "width:500px" } })

Answer 1

Since MVC 5.1, you can pass in custom attributes with using the htmlAttributes as a key:

@Html.EditorFor(model => model.ClienteNuevo, 
    new { htmlAttributes = new { @class = "form-control" } })

In older MVC versions there is no way to add html attributes with the EditorFor method.
You should create a custom editor template or use Html.TextboxFor istead of EditorFor. You should check these topics topic1, topic2.