How do I turn a relative URL into a full URL?

Question

This is probably explained more easily with an example. I'm trying to find a way of turning a relative URL, e.g. "/Foo.aspx" or "~/Foo.aspx" into a full URL, e.g. http://localhost/Foo.aspx. That way when I deploy to test or stage, where the domain under which the site runs is different, I will get http://test/Foo.aspx and http://stage/Foo.aspx.

Any ideas?

Answer 1

Request.Url.Host

Answer 2

Have a play with this (modified from here)

public string ConvertRelativeUrlToAbsoluteUrl(string relativeUrl) {
    if (Request.IsSecureConnection)
        return string.Format("https://{0}{1}", Request.Url.Host, Page.ResolveUrl(relativeUrl));

    return string.Format("http://{0}{1}", Request.Url.Host, Page.ResolveUrl(relativeUrl));
}

Answer 3

Use the .NET Uri class to combine your relative path and the hostname.
http://msdn.microsoft.com/en-us/library/system.uri.aspx

Answer 4

The by far easiest way is to use the class VirtualPathUtility and its method ToAbsolute:

string absolutePath = VirtualPathUtility.ToAbsolute(appRelativePath);

Answer 5

This is my helper function to do this

public string GetFullUrl(string relativeUrl) {
    string root = Request.Url.GetLeftPart(UriPartial.Authority);
    return root + Page.ResolveUrl("~/" + relativeUrl) ;
}