Hey

I have created a theme selector that reads the themes in the App_Themes folder and displays them in a dropdown list on a web page.I want users to be able to select the theme they prefer and change the whole pages appearance
to that theme.

The default theme is working fine when the page is first loaded and displayed BUT when i try to change the theme by selecting a different theme from the dropdowlist,the page displays without any formatting.ie the other themes other than the default are not being picked up by the page.

The code for the theme selector user control is as follows:

 ddlThemes.DataSource = Helpers.GetThemes();
        ddlThemes.DataBind();
        ddlThemes.SelectedValue = this.Page.Theme;

The GetThemes method in the Helpers class is as follows:

  public static string[] GetThemes()
        {
            if (HttpContext.Current.Cache["SiteThemes"] != null)
            {
                return (string[])HttpContext.Current.Cache["SiteThemes"];
            }
            else
            {
                string themesDirPath = HttpContext.Current.Server.MapPath("~/App_Themes");
                // get the array of themes folders under /app_themes
                string[] themes = Directory.GetDirectories(themesDirPath);
                for (int i = 0; i <= themes.Length - 1; i++)
                    themes[i] = Path.GetFileName(themes[i]);
                // cache the array with a dependency to the folder
                CacheDependency dep = new CacheDependency(themesDirPath);
                HttpContext.Current.Cache.Insert("SiteThemes", themes, dep);
                return themes;
            }

        }

I would greatly appreciate your help in resolving this problem

Thanks

Tawanda

I had this problem before, when I copied info from the chapter-by-chapter code that somebody posted. I solved this by making sure every one of my pages inherited from the custom BasePage class. Meaning, my code-behind file, for my contact page for example, has the class statement written like this:

public partial class contact : BasePage

instead of just

public partial class contact : Page

It's the Basepage class that has that "OnPreInit" method that actually assigns the theme.
Hope this helps.

Apparently my default.aspx actually inherits from the BasePage as you said but i still cant change the theme.Thanks for your time anyway.

Sorry--I should have read your post more carefully. have you completely finished chapter 2? Well, look on page 40 and you'll see that your missing a line in that themeselector code you posted. it should be like this:

if (Globals.themeselectid.Length == 0) Globals.themeselectid = ddlThemes.UniqueID;
//then put the rest of your code:
ddlthemes.Datasource...;
...

If you don't already have that line, this probably also means you need that other snippet on page 40 that declares that global variable (the "themeselectid" in my example above. Use whatever name you like, just be consistent). That declaration is in Globals.cs in the App_Code folder.

Hi,

I think I have a similar problem to this. When trying to run the page I get the following compilation error:

 Compiler Error Message: CS1002: ; expected
 referring to line: public static string[] GetThemes()

I have gone back to the book and checked that I have done all the stages, but can only think I must have missed something.

Any help would be appreciated.
Thanks.

False alarm - I've sorted that bit now and moved onto my next head scratching moment.

Thanks