How do I find the absolute url of an action in ASP.NET MVC?

Click here for more information, but esentially there is no need for extension methods. It's already baked in, just not in a very intuitive way.

Url.Action("Action", null, null, Request.Url.Scheme);

Extend the UrlHelper

namespace System.Web.Mvc
{
    public static class HtmlExtensions
    {
        public static string AbsoluteAction(this UrlHelper url, string action, string controller)
        {
            Uri requestUrl = url.RequestContext.HttpContext.Request.Url;

            string absoluteAction = string.Format(
                "{0}://{1}{2}",
                requestUrl.Scheme,
                requestUrl.Authority,
                url.Action(action, controller));

            return absoluteAction;
        }
    }
}

Then call it like this

<%= Url.AbsoluteAction("Dashboard", "Account")%>

EDIT - RESHARPER ANNOTATIONS

The most upvoted comment on the accepted answer is This answer is the better one, this way Resharper can still validate that the Action and Controller exists. So here is an example how you could get the same behaviour.

using JetBrains.Annotations

namespace System.Web.Mvc
{
    public static class HtmlExtensions
    {
        public static string AbsoluteAction(
            this UrlHelper url,
            [AspMvcAction]
            string action,
            [AspMvcController]
            string controller)
        {
            Uri requestUrl = url.RequestContext.HttpContext.Request.Url;

            string absoluteAction = string.Format(
                "{0}://{1}{2}",
                requestUrl.Scheme,
                requestUrl.Authority,
                url.Action(action, controller));

            return absoluteAction;
        }
    }
}

Supporting info:

• Providing Intellisense, Navigation and more for Custom Helpers in ASP.NET MVC

<%= Url.Action("About", "Home", null, Request.Url.Scheme) %>
<%= Url.RouteUrl("Default", new { Action = "About" }, Request.Url.Scheme) %>