InvalidOperationException: The following sections have been defined but have not been rendered by the page at '/Views/Shared/UserLayout.cshtml'

Question

I'm trying to convert an ASP.NET MVC project to ASP.NET Core MVC. I have done most of the work but got stuck in a weird issue.

My project has a view User.cshtml and a layout page UserLayout.cshtml, based on an API call I was returning the view and its master page through return View("User", "UserLayout"); in ASP.NET MVC.

The method expects a view name and a master name. This overload doesn't exists anymore in ASP.NET Core MVC so I have set the layout on top of my User.cshtml page like this:

@{ Layout="~/Views/Shared/UserLayout.cshtml"; }

and returned just the view name from my controller.

Now my layout page contains Kendo tabstrip and in its content I'm rendering sections like @RenderSection("HomeTab", true) which are defined in UserLayout.cshmtl @section HomeTab {}. This is working completely fine with the ASP.NET MVC project, but when I run the ASP.NET Core MVC project, I'm getting this exception:

InvalidOperationException: the following sections have been defined but have not been rendered by the page at '/Views/Shared/AgentLayout.cshtml': 'HomeTab'. To ignore an unrendered section call IgnoreSection("sectionName").

I have tried removing the section, changing the required attribute to false but the error remains. It seems I didn't need to convert views from .NET to .NET Core but it's this small thing that has got me stuck.

Answer 1

I found a solution to this posting it here for anyone stuck with the same issue.

I created a razor code block above my kendo tab strip @{} and after the code block closes I added a .Render() function and so far my code is running as expected.

 @{
                    Html.Kendo().TabStrip()
                        .Name("tabstrip")
                        .Events(events => events
                        .Select("onTabSelected")
                        .Activate("onTabActivated")
                        .ContentLoad("onTabContentLoaded")
                        .Error("onTabError")
    
                        )
                        .Animation(animation =>
                        {
                            animation.Enable(false);
                        })
                        .Items(tabstrip =>
                        {
                            if (!ViewBag.isOffline)
                            {
                                tabstrip.Add().Text("Home")
                        .HtmlAttributes(new { id = "hometabid" })
                        .Selected(true)
                        .ImageUrl(Url.Content("~/Content/Images/HomeTabIcon.png")).ImageHtmlAttributes(new { id = "hometabimgid" })
                        .Content(
                    @<text>
                               @RenderSection("HomeTab",false)
                            </text>
                    ).ContentHtmlAttributes(new { @style = "overflow: auto;" });
                            }
                            }
                        }).Render();
                        }
                @RenderBody()