Search code examples
c#.netblazorblazor-server-side.net-8.0

Blazor - .NET 8.0 - InvalidOperationException: Cannot find the fallback endpoint specified by route values: { page: /_Host, area: }

I am programming a website in the .NET framwork Blazor (.NET 8.0). I wanted to add an login via Active Directory and after this I got the following error:

System.InvalidOperationException: Cannot find the fallback endpoint specified by route values: { page: /_Host, area:  }.
   at Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.DynamicPageEndpointMatcherPolicy.ApplyAsync(HttpContext httpContext, CandidateSet candidates)
   at Microsoft.AspNetCore.Routing.Matching.DfaMatcher.SelectEndpointWithPoliciesAsync(HttpContext httpContext, IEndpointSelectorPolicy[] policies, CandidateSet candidateSet)
   at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.<Invoke>g__AwaitMatch|10_1(EndpointRoutingMiddleware middleware, HttpContext httpContext, Task matchTask)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

After long searching through the internet I found a solution for the problem but it didnt worked for me. The solution was the following one:

<PropertyGroup>
    <UseRazorSourceGenerator>false</UseRazorSourceGenerator>
</PropertyGroup>`

This should be added to the project.csproj. Maybe someone can tell me what my mistake is and help me to solve it.

_Host.cshtml:

@page "/"
@namespace Berhub
@using Berhub.Pages
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
@{
    Layout = null;
}

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>BERHub</title>
    <base href="~/" />
    <link href="css/bootstrap/bootstrap.min.css" rel="stylesheet" />
    <link href="css/app.css" rel="stylesheet" />
</head>
<body>
    <app>
        <component type="typeof(App)" render-mode="ServerPrerendered" />
    </app>

    <script src="_framework/blazor.server.js"></script>
    
</body>
</html>

Program.cs:

using Berhub;
using Berhub.Models;
using berhub.Components;
using Dapper;
using Berhub.DataAccessLayer.DataAccessLayer;
using Berhub.DataAccessLayer.SqlDataAccess;
using Radzen;
using Radzen.Blazor;
using Microsoft.Extensions.DependencyInjection;
using Berhub.DataAccessLayer.Repositories;
using Microsoft.AspNetCore.Authentication.Negotiate;
using Microsoft.AspNetCore.Authorization;
using Microsoft.Extensions.Configuration;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();

builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents();
builder.Services.AddRadzenComponents();

builder.Services.AddScoped<IWindowsServerData, WindowsServerData>();
builder.Services.AddScoped<ISqlDataAccess, SqlDataAccess>();
builder.Services.AddScoped<IHostnameData<HostnameModel>, HostnameData>();
builder.Services.AddScoped<IAppointment<Appointment>, Berhub.DataAccessLayer.DataAccessLayer.AppointmentData>();

var configuration = builder.Configuration;
builder.Services.AddAuthentication(NegotiateDefaults.AuthenticationScheme).AddNegotiate();            // Windows authentication  may not be applied with Kestrel without this line                    
builder.Services.AddAuthorization(
    options =>{
    options.AddPolicy("KeyUsers", policy =>
    policy.RequireRole(configuration.GetSection("ActiveDirectory")["KeyUsers"]));
});

/**builder.Services.AddRazorPages(options =>
{
    options.RootDirectory = "/Components";
});**/
builder.Services.AddServerSideBlazor();


var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error", createScopeForErrors: true);
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseAntiforgery();
app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();

app.MapRazorPages();
app.MapBlazorHub();
app.MapFallbackToPage("/_Host"); // Pfad zur _Host.cshtml anpassen


app.Run();

index.razor (login):

@page "/"
@attribute [StreamRendering]

<PageTitle>Home</PageTitle>

<AuthorizedView Policy="KeyUsers">
    <Authorized>

    </Authorized>

    <NotAuthorized>



    <link rel="stylesheet" href="Login.razor.css" />


        <div class= "container">
            <form method = "post">
                <fieldset>
                    <legend>Anmelden</legend>
                    <div class="nutznername">
                        <label for="username">Benutzername: </label>
                        <input type="text" name="username" value=""/>
                    </div>
                    <div class="passwort">
                        <label for="password">Passwort: </label>
                        <input type="password" name="password">
                    </div>
                    <div class="bestätigen">
                        <label>&nbsp;</label>
                        <input type="submit" value="Submit" class="submit" />
                    </div>
                </fieldset>
            </form> 
        </div>

    </NotAuthorized>
</AuthorizedView>

The Pictures shows the project structure of my project.

Solution

  • You removed the codes that configured the RootDirectory of razor pages:

    /**builder.Services.AddRazorPages(options =>
{
    options.RootDirectory = "/Components";
});**/

    According to the codes above,your _host.cshtml should be in Components folder.Try recover the codes and put your _host.cshtml in the right place

    If you still get the error,please show us the structure of your project

    A minimal example on myside:

    Program.cs:

    var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents();
builder.Services.AddRazorPages(options =>
{
options.RootDirectory = "/Components/Pages";
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error", createScopeForErrors: true);
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();

app.UseStaticFiles();
app.UseAntiforgery();

app.MapRazorComponents<App>()
    .AddInteractiveServerRenderMode();
app.MapFallbackToPage("/_Host");
app.Run();

    Project structure:

    enter image description here

    _Host.cshtml:

    @page "/"

@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
@{
    Layout = null;
}

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>BERHub</title>
    <base href="~/" />
    <link href="css/bootstrap/bootstrap.min.css" rel="stylesheet" />
    <link href="css/app.css" rel="stylesheet" />
</head>
<body>
    FallBack Page

    

</body>
</html>

    It would go to the fall backpage when it can't find the component for current route:

    enter image description here