Can't inject 2sxc app into DNN skin file - "error BC30451: 'this' is not declared."

Question

DNN Version: 9.11.0
2sxc Version: 14.11.0

I'm trying to use 2sxc's IRenderService to render a 2sxc module within a DNN skin file (.ascx). I've been using the following resources for reference:

• https://wolfxmachina.com/blog/category/video/how-to-inject-2sxc-apps-into-a-dnn-theme-and-why-you-would-want-to-do-that
• https://2sxc.org/en/blog/post/deep-dnn-skin-and-module-integration-towel-day-2022
• Error when trying to inject 2sxc app into DNN template

Each of these resources seems to indicate the same essential parts to get this to work:

These three namespaces:

<%@ Import Namespace="DotNetNuke.Entities.Modules" %>
<%@ Import Namespace="ToSic.Sxc.Dnn" %>
<%@ Import Namespace="ToSic.Sxc.Services" %>

And the following line of code: <%= this.GetScopedService<IRenderService>().Module(8196, 21481) %>

However, whenever I add these parts to my skin file and open a live page using that skin, a 500 error is returned by the server with the following error message in the URL: "Object reference not set to an instance of an object".

<%@ Control language="vb" AutoEventWireup="false" Explicit="True" Inherits="DotNetNuke.UI.Skins.Skin" %>
<%@ Register TagPrefix="dnn" TagName="LANGUAGE" Src="~/Admin/Skins/Language.ascx" %>
<%@ Register TagPrefix="dnn" TagName="LOGO" Src="~/Admin/Skins/Logo.ascx" %>
<%@ Register TagPrefix="dnn" TagName="SEARCH" Src="~/Admin/Skins/Search.ascx" %>
<%@ Register TagPrefix="dnn" TagName="NAV" Src="~/Admin/Skins/Nav.ascx" %>
<%@ Register TagPrefix="dnn" TagName="TEXT" Src="~/Admin/Skins/Text.ascx" %>
<%@ Register TagPrefix="dnn" TagName="BREADCRUMB" Src="~/Admin/Skins/BreadCrumb.ascx" %>
<%@ Register TagPrefix="dnn" TagName="USER" Src="~/Admin/Skins/User.ascx" %>
<%@ Register TagPrefix="dnn" TagName="LOGIN" Src="~/Admin/Skins/Login.ascx" %>
<%@ Register TagPrefix="dnn" TagName="LEFTMENU" Src="~/Admin/Skins/LeftMenu.ascx" %>
<%@ Register TagPrefix="dnn" TagName="LINKS" Src="~/Admin/Skins/Links.ascx" %>
<%@ Register TagPrefix="dnn" TagName="PRIVACY" Src="~/Admin/Skins/Privacy.ascx" %>
<%@ Register TagPrefix="dnn" TagName="TERMS" Src="~/Admin/Skins/Terms.ascx" %>
<%@ Register TagPrefix="dnn" TagName="COPYRIGHT" Src="~/Admin/Skins/Copyright.ascx" %>
<%@ Register TagPrefix="dnn" TagName="STYLES" Src="~/Admin/Skins/Styles.ascx" %>
<%@ Register TagPrefix="dnn" TagName="LINKTOMOBILE" Src="~/Admin/Skins/LinkToMobileSite.ascx" %>
<%@ Register TagPrefix="dnn" Namespace="DotNetNuke.Web.DDRMenu.TemplateEngine" Assembly="DotNetNuke.Web.DDRMenu" %>
<%@ Register TagPrefix="dnn" TagName="MENU" src="~/DesktopModules/DDRMenu/Menu.ascx" %>
<%@ Register TagPrefix="dnn" TagName="CONTROLPANEL" Src="~/Admin/Skins/controlpanel.ascx" %>
<%@ Register TagPrefix="dnn" Namespace="DotNetNuke.Web.Client.ClientResourceManagement" Assembly="DotNetNuke.Web.Client" %>
<%@ Import Namespace="DotNetNuke.Entities.Modules" %>
<%@ Import Namespace="ToSic.Sxc.Dnn" %>
<%@ Import Namespace="ToSic.Sxc.Services" %>

<%= this.GetScopedService<IRenderService>().Module(8196, 21481) %>
...

Looking at the DNN admin logs, I get the following message:

Message:Unhandled error loading page.

StackTrace:

...error BC30451: 'this' is not declared. It may be inaccessible due to its protection level.

InnerStackTrace:

at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath)
at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate)
at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate)
at System.Web.Compilation.BuildManager.GetVPathBuildResult(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean ensureIsUpToDate)
at System.Web.UI.TemplateControl.LoadControl(VirtualPath virtualPath)
at DotNetNuke.UI.ControlUtilities.LoadControl\[T\](TemplateControl containerControl, String ControlSrc)
at DotNetNuke.UI.Skins.Skin.LoadSkin(PageBase page, String skinPath)

What does it mean by 'this' is not declared? Am I missing a reference? How can I get this to work as smoothly as it does in the 3 resources I mentioned above?

Answer 1

See iJungleBoy's comments for a breakdown of the issue.

Ultimately, it appears that 2sxc services can only be activated in skins/modules whose language is set to C#. Updating my skin's language from VB to C# solved the issue.

<%@ Control Language="c#" AutoEventWireup="false" Explicit="True" Inherits="DotNetNuke.UI.Skins.Skin"%>