Early this month I started a new ASP.NET Core application, which I'm writing in .NET 8. I used this because I've got to use Windows Authentication. However, I also want to learn Blazor, so I added that to the project. Now I'm gettings errors in the RouteView.razor file and the Routes.razor file. Here's the RouteView.razor file: <RouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" /> The errors it is raising are: RZ9985 Multiple components use the tag 'RouteView' (two of this error) CS1061 'RouteView' does not contain a definition for 'RouteData' and no accessible extension method 'RouteData' accepting a first argument of type 'RouteView' could be found CS0103 The name 'routeData' does not exist in the current context (two of this error) CS1061 'RouteView' does not contain a definition for 'DefaultLayout' and no accessible extension method 'DefaultLayout' accepting a first argument of type 'RouteView' could be found CS0246 The type or namespace name 'MainLayout' could not be found (two of this error) And here's what's in the Routes.razor file: <Router AppAssembly="typeof(Program).Assembly"> <Found Context="routeData"> <RouteView RouteData="routeData" /> <FocusOnNavigate RouteData="routeData" Selector="h1" /> </Found> </Router> And the error its raising is:- RZ9985 Multiple components use the tag 'RouteView' I'm not sure why it is raising these errors. I am still too new to Blazor. Is it because I created the ASP.NET Core project first, then added Blazor?

no. its your blazer code. normally, the App.Razor references the Routes.Razor, and Routes references the layout. also check your _imports.razor. I'd create a new blazor app from the template, and compare to your project. (also try deleting obj & bin folders, then rebuild). note: windows authentication is implemented by IIS, and the user handle is passed to asp.net. the default builder normally included this support.

I'm getting errors when trying to add Razor to an ASP.NET Core MVC project

Falanga, Rod, DOH 215

Early this month I started a new ASP.NET Core application, which I'm writing in .NET 8. I used this because I've got to use Windows Authentication. However, I also want to learn Blazor, so I added that to the project.

Now I'm gettings errors in the RouteView.razor file and the Routes.razor file. Here's the RouteView.razor file:

<RouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" />

The errors it is raising are:

RZ9985 Multiple components use the tag 'RouteView' (two of this error)
CS1061 'RouteView' does not contain a definition for 'RouteData' and no accessible extension method 'RouteData' accepting a first argument of type 'RouteView' could be found
CS0103 The name 'routeData' does not exist in the current context (two of this error)
CS1061 'RouteView' does not contain a definition for 'DefaultLayout' and no accessible extension method 'DefaultLayout' accepting a first argument of type 'RouteView' could be found
CS0246 The type or namespace name 'MainLayout' could not be found (two of this error)

And here's what's in the Routes.razor file:

<Router AppAssembly="typeof(Program).Assembly">
    <Found Context="routeData">
        <RouteView RouteData="routeData" />
        <FocusOnNavigate RouteData="routeData" Selector="h1" />
    </Found>
</Router>

And the error its raising is:- RZ9985 Multiple components use the tag 'RouteView'

I'm not sure why it is raising these errors. I am still too new to Blazor. Is it because I created the ASP.NET Core project first, then added Blazor?

SurferOnWww 3,201 Reputation points

2024-07-29T23:12:01+00:00

I'm getting errors when trying to add Razor to an ASP.NET Core MVC project

Are you trying to add new Razor component of Blazor app to the existing solution / project of ASP.NET Core MVC? Why don't you create new Blazor solution / project separate from the MVC? You say "I also want to learn Blazor". I guess that you will be able to learn Blazor with a separate solution. Is your purpose of learning something special which requires addition of Razor component to MVC?
Falanga, Rod, DOH 215 Reputation points

2024-07-30T14:02:02.1+00:00

@SurferOnWww no, it's more that I can't remember whether I created an ASP.NET MVC Core app, or an ASP.NET Razor Core app. I started this weeks ago, then was pulled off to work on some urgent projects. I was following along on a tutorial, but can't find that now, either.

Very frustrating.
Falanga, Rod, DOH 215 Reputation points

2024-07-30T16:17:09.79+00:00
I've done more digging and have found the article I was following in order to add Blazor to an ASP.NET Core application. It's an article named, "Integrate ASP.NET Core Razor components into ASP.NET Core apps". I have a link to the interactive server-side rendering on that page.

I've been trying different things, which only lead to confusion, because what I'm using is .NET 8, but a lot of what I get when I search for help is .NET 3.
And I've got an error in the Program.cs file, which I didn't report before. (I just discovered it.) Here's the relevant lines of code:

app.MapRazorComponents<App>() .AddInteractiveServerRenderMode() .AddInteractiveWebAssemblyRenderMode() .AddAdditionalAssemblies(typeof(AspNetCoreWithWindowsAuth.Client._Imports).Assembly); app.Run();

The line AddInteractiveWebAssemblyRenderModer() raises an error that says:

CS1061 'RazorComponentsEndpointConventionBuilder' does not contain a definition for 'AddInteractiveWebAssemblyRenderMode' and no accessible extension method 'AddInteractiveWebAssemblyRenderMode' accepting a first argument of type 'RazorComponentsEndpointConventionBuilder' could be found (are you missing a using directive or an assembly reference?)

1 answer

Bruce (SqlWork.com) 66,706 Reputation points

2024-07-29T21:26:00.59+00:00

no. its your blazer code. normally, the App.Razor references the Routes.Razor, and Routes references the layout. also check your _imports.razor.

I'd create a new blazor app from the template, and compare to your project. (also try deleting obj & bin folders, then rebuild).

note: windows authentication is implemented by IIS, and the user handle is passed to asp.net. the default builder normally included this support.
Please sign in to rate this answer.
Falanga, Rod, DOH 215 Reputation points

2024-07-30T14:03:54.2766667+00:00

I'll try what you've suggested, Bruce. Good idea on deleting the obj and bin folders.
Sign in to comment

Use comments to ask for clarification, additional information, or improvements to the question.

Share via

I'm getting errors when trying to add Razor to an ASP.NET Core MVC project

1 answer

Your answer