Why does ASP.Net rewrite relative paths for runat=server anchor controls?

Question

I have my UserControls in a ~/Controls folder in my solution:

/Controls/TheControl.ascx

If specify the following:

<a id="theId" runat="server" href="./?pg=1">link text</a>

ASP.Net seems to want to rewrite the path to point to the absolute location. For example, If the control is on site.com/products/fish/cans.aspx the link href will be rewritten to read

<a id="munged_theId" href="../../Controls/?pg=1>link text</a>

Why does Asp.Net rewrite these control paths, and is there an elegant way to fix it?

I just want the anchor control to spit out exactly what I tell it to!!! Is that so hard?

EDIT:

I've basically done what Kelsey suggested. I knew I could do it this way, but I don't like adding markup in my code when I want something relatively simple. At least it solves the problem:

Aspx page:

<asp:PlaceHolder ID="ph" runat="server"></asp:PlaceHolder>

Code-behind:

var anchor = new HtmlGenericControl("a") { InnerText = "Previous" + " " + PageSize) };
anchor.Attributes["href"] = "?pg=" + (CurrentPage - 1);
anchor.Attributes["class"] = "prev button";
ph.Controls.Clear();
ph.Controls.Add(anchor);

As you can see by the amount of code needed for what is essentially supposed to be be a simple and light-weight anchor, it's not the most optimal solution. I know I could use a Literal but I figured this was cleaner as I'm adding more than one anchor.

I would be interesting in knowing WHY ASP.Net takes over and tries to fix my URL, though.

Answer 1

Why do you have runat="server" and no ID defined? Do you need to access it server side? If you remove the runat="server" everything will work as expected.

For more information regardinging how ASP.NET handles paths check out this MSDN article.

Edit: You can get around the problem then by using a Literal control and then outputing the raw <a href... to it.

Eg:

<asp:Literal ID="myLiteral" runat="server" />

myLiteral.Text = "<a href=\"./?pg=1\">link text</a>";

Then you can set the visible property on the Literal however you want.

Answer 2

I know this is a bit of an old topic, but I was running into this problem as well and in the end went with a similar solution, but was able to save a few lines of code by doing this in the ascx:

<anchor id="myAnchor" runat="server" href="xxx">link text</anchor>

Then in the code behind, I referenced it using an HtmlGenericControl and can then do this:

myAnchor.TagName = "a";
// other properties set as needed

Anyway, I thought I'd post in case anyone else stumbles in here with the same issue.

Answer 3

Best bet is to make everything app root relative using the magic ~/ lead-in to the url. That tends to keep stuff straight.