我可以在 MVC3中添加一个类到 HTMLActionLink 吗

According to the documentation, this should do the trick:

Html.ActionLink("LinkText", "Action", "Controller", new { }, new {@class="css class"})

Edit: Thanks for noticing Dampe, I updated the code sample.

Yes, you can just add another parameter with object representing css class:

Html.ActionLink("Create New", "Create", CONTROLLERNAME, null, new { @class= "yourCSSclass"} )

It can be translated to:

Html.ActionLink(link text, action name, controller name, route values object, html attributes object)

Edit:

To add custom styles, use this:

Html.ActionLink(
"Create New",
"Create",
CONTROLLERNAME,
null,
new { @class= "yourCSSclass", @style= "width:100px; color: red;" }
)

You can use the ActionLink overload which takes an htmlAttributes parameter to add a class to the generated element:

Html.ActionLink("Create New", "Create", new {}, new { @class = cssClass });

Html.ActionLink("Create New", "Create", null, htmlAttributes: new { @class = "className" })

@Html.ActionLink("ClickMe",  // link text
"Index", // action name
"Home",  // controller
new { id = 2131 }, // (optional) route values
new { @class = "someClass" }) // html attributes