ASP.NET - Avoid hardcoding paths

I'd suggest that you derive your own class ("MyPageClass") from the Page class and include this method there:

public class MyPageClass : Page
{
    private const string productListPagePath = "~/products/list.aspx?category=";
    protected void GotoProductList(string category)
    {
         Response.Redirect(productListPagePath + category);
    }
}

Then, in your codebehind, make sure that your page derives from this class:

 public partial class Default : MyPageClass
 {
      ...
 }

within that, you can redirect just by using:

 GotoProductList("Books");

Now, this is a bit limited as is since you'll undoubtedly have a variety of other pages like the ProductList page. You could give each one of them its own method in your page class but this is kind of grody and not smoothly extensible.

I solve a problem kind of like this by keeping a db table with a page name/file name mapping in it (I'm calling external, dynamically added HTML files, not ASPX files so my needs are a bit different but I think the principles apply). Your call would then use either a string or, better yet, an enum to redirect:

 protected void GoToPage(PageTypeEnum pgType, string category)
 {
      //Get the enum-to-page mapping from a table or a dictionary object stored in the Application space on startup
      Response.Redirect(GetPageString(pgType) + category);  // *something* like this
 }

From your page your call would be: GoToPage(enumProductList, "Books");

The nice thing is that the call is to a function defined in an ancestor class (no need to pass around or create manager objects) and the path is pretty obvious (intellisense will limit your ranges if you use an enum).

Good luck!