Data dash attributes in ASP.NET MVC

http://stackoverflow.com/questions/4844001/html5-data-with-asp-net-mvc-textboxfor-html-attributes

You could use underscore (_) and the helper is intelligent enough to do the rest:

Html.TextBoxFor(
    model => model.Country.CountryName, 
    new { data_url = Url.Action("CountryContains", "Geo") }
)

And for those who want to achieve the same in pre ASP.NET MVC 3 versions they could:

<%= Html.TextBoxFor(
    model => model.Country.CountryName, 
    new Dictionary<string, object> { 
        { "data-url", Url.Action("CountryContains", "Geo") } 
    }
) %>