I have a problem with using user controls for common page elements such as navigation bars. If I use the control in subfolders of the site, as is necessary for a large website, the links don't work. This can be worked around by using root-relative paths, e.g. instead of "Images/Navbar.gif" using "/MySite/Images/Navbar.gif".

However, this then creates a deployment problem. Let's say I want to deploy the site on a host, e.g. www.mysite.com, I don't want it to have to be www.mysite.com/MySite in order for the links to work!

Is there any way of working around this, which allows the links to work properly in the Visual Studio Web Forms designer?

Any help is much appreciated.

Indeed there is a very easy fix for this. ASP.Net has eliminated a major problem from ASP that I'm sure many people have had when building sites with the MS Visual tools which inevitably have a subdirectory where the project exists and a corresponding virtual directory in IIS. (In ASP we had to write complicated functions to deal with this for us.)

They have taken the hint from the unix world and implemented "~" as a sort of "home" placeholder character.

This functionality appears to be built into the server controls that need a virtual/relative path to resources (images, usercontrols, links, etc) If you are using one of these server controls you need only to define the resource path like this...

    "~/mypage.aspx"

Make your resource path attribute start with "~/" (establishing the root of the project) then just provide the full path within the hierachy of your project.

    "~/images/someimage.gif"
    "~/afolder/somepage.aspx"

These references will work from anywhere within your application because it will replace "~" with the application root if there is any. So the items above become:

    "/myWebApplication/mypage.aspx"
    "/myWebApplication/images/someimage.gif"
    "/myWebApplication/afolder/somepage.aspx"

Furthermore, you could even put user controls in a folder for organization. When you refer to the controls source page you just do the same thing:

In an ASPX file using the tag registration directive:
<%@ Register TagPrefix="uc" Tagname="myUserControl" Src="~/UserControlFolder/myUserControl.ascx" %>

    or

In code-behind:
LoadControl("~/UserControlFolder/myUserControl.ascx")

Unfortunately, if you want to use this functionality in static HTML you run into a little problem as there is no way to do the replacement of "~". But... there is a method off of the Control object (from which Page and UserControl are derived) called "ResolveURL". You can call this with the same formatted string ("~/...") and it will resolve it to the application root. I believe (no guarantees) that you could even do this within an ASPX (do it ASP style):

<a href="<%=ResolveURL("~/folder/page.aspx")%>">My Link</a>

Fortunately, none of this is a workaround, it's built in but poorly documented. I came across is looking at someone's code regarding something totally unrelated. I recognized what it was from my limited *nix knowledge and tried it out. Now I am in the habit of using it consistently throughout my applications so there's never a possibility of broken resource references.

Peter