SharePoint 2010 THEMES - Retrieve, Upload and Apply programmatically

protected void Page_Load(object sender, EventArgs e)

{

 try

 {

  if (!(Page.IsPostBack))

  {

   SPSecurity.RunWithElevatedPrivileges(delegate()

   {

    using (SPSite pageLoadSite = new SPSite(SPContext.Current.Site.ID))

    {

     pageLoadSite.AllowUnsafeUpdates = true;

     using (SPWeb pageLoadWeb = pageLoadSite.OpenWeb())

     {

      pageLoadWeb.AllowUnsafeUpdates = true;

      GetThemes(pageLoadWeb);

      UploadThemeFileInThemeGallery(pageLoadWeb)

      SetTheme(pageLoadWeb);

      pageLoadWeb.AllowUnsafeUpdates = false;

     }

    pageLoadSite.AllowUnsafeUpdates = false;

    }

   });

  }

 }

 catch (Exception ex)

 {

  Throw ex;

 }

}

/// <summary>

/// Gets the list of themes from themes gallery.

/// </summary>

/// <param name="web"></param>

private void GetThemes(SPWeb web)

{

 try

 {

  SPWeb rootWeb = web;

  //Themes are available only at root-web level.

  if (!web.IsRootWeb)

    rootWeb = web.Site.RootWeb;

  SPDocumentLibrary themeGallery =  

        (SPDocumentLibrary)
                rootWeb.GetCatalog(SPListTemplateType.ThemeCatalog);

  if (themeGallery != null)

  {

   foreach (SPListItem themeItem in themeGallery.Items)

   {

     string themeName = themeItem.Name;

   }

  }

  else { // "No themes available for site " }

  //gets current applied theme Name

  string currentAppliedTheme = string.Empty;

  string themeurl = ThmxTheme.GetThemeUrlForWeb(web); //gets current 

                                                      // theme

  if (!string.IsNullOrEmpty(themeurl))

  {

   ThmxTheme theme = ThmxTheme.Open(web.Site, themeurl);

   currentAppliedTheme = theme.Name; //Gets the name of theme

  }

 }

 catch (Exception ex)

 {

  throw new Exception("Unable to get theme for site " + web.Title + ". Error: " + ex.Message);

 }

}

/// <summary>

/// Sets theme for the site.

/// </summary>

/// <param name="web">Website for which master page is to be set.</param>

private void SetTheme(SPWeb web)

{

 try

 {

  ThmxTheme theme = ThmxTheme.Open(web.Site, "_catalogs/theme/" + "MyTheme.thmx");

theme.ApplyTo(web, false);

web.Update();

 }

 catch (Exception ex)

 {

 throw new Exception("Unable to set theme for site " + web.Title + ". Error: " + ex.Message);

 }

}

/// <summary>

/// Uploads new theme file in theme gallery, overwrites, if already exists.

/// </summary>

/// <param name="web">Website for which master page is to be set.</param>

private void UploadThemeFileInThemeGallery(SPWeb web)

{

 try

 {

  //fuTheme is a fileupload control in my project

  SPDocumentLibrary themeGallery = (SPDocumentLibrary)web.GetCatalog(SPListTemplateType.ThemeCatalog);

  themeGallery.RootFolder.Files.Add(themeGallery.RootFolder.ServerRelativeUrl + "/" + fuTheme.FileName, fuTheme.FileBytes, true);

  themeGallery.Update();

 }

 catch (Exception ex)

 {

  throw new Exception("Unable to upload theme for site " + web.Title + ". Error: " + ex.Message);

 }

}