How do you add a CSS class name to an ASP.NET MVC 3 Url.Action link?

Url.Action does not create any html element, it only creates a URL, which is why it's called Url.Action, and not Html.Action... (Html.Action is something totally different).

If you want css on a link that you use Url.Action on, just do this:

<a href="@Url.Action("Action", "Controller")" class="myclass">My Link<a>

Alternatively, you can use Html.ActionLink

@Html.ActionLink("My Link", "Action", "Controller", null, new { @class="myclass" })

The Url.Action helper will simply print the url not the full anchor.

Your two options are:

@Html.ActionLink("BAR", "index","home", new { @class = "FOO" })

• note the use of the @ symbol on the class as class is a reserved keyword

and (using the Url.Action helper)

<a href="@Url.Action("Index", "Home", new { page })" class="FOO">BAR</a>

Here's what I do:

I have this class:

public class HtmlValues : Dictionary<string,object>
{
    public HtmlValues Class(string ClassName)
    {
        if (this.ContainsKey("class"))
        {
            ClassName = String.Format("{0} {1}", this["class"], ClassName);
            this.Remove("class");
        }
        return this.WithValue("class", ClassName);
    }
    public HtmlValues Name(string Name)
    {
        return this.WithValue("name", Name);
    }
    public HtmlValues Style(string Style)
    {
        return this.WithValue("style", Style);
    }
    public HtmlValues MaxLength(int Length)
    {
        return this.WithValue("maxlength", Length.ToString());
    }
    public HtmlValues RTL()
    {
        return this.WithValue("dir", "rtl");
    }
    public HtmlValues With(string Attribute, string Value)
    {
        return this.WithValue(Attribute, Value);
    }

    public static HtmlValues WithClass(string CssClass)
    {
        return new HtmlValues().Class(CssClass);
    }

    public HtmlValues Data(string key, string value)
    {
        return this.WithValue("data-" + key, value);
    }
}

With this extension method:

public static class Extensions
{
    public static T WithValue<T>(this T dict, string key, object value) where T : IDictionary<string, object>
    {
        dict.Add(key, value);
        return dict;
    }
}

Then my Razor looks like this:

@Html.TextBoxFor(model => model.SomeProperty, HtmlValues.WithClass("SomeClass"))

This may seem like overkill, but it is pretty nice in practice, as it lets you chain add attributes/values to the element in a nice fluent, meaningful to the reader fashion.

@Html.TextBoxFor(model => model.SomeProperty, 
    HtmlValues.WithClass("SomeClass")
              .Class("someotherClass")
              .Data("Some-Jquery-Data-Thing")
              .With("Nonstandard-Attribute","Its-Value"))