asp-controller 和 asp-action 在 ASP.NET Core 3.1 Razor Pages 应用程序中不起作用

Question

I have an ASP.NET Core 3.1 Razor Pages app which allows users to log in and out.

To log out, I have the following Controller:

public sealed class AccountController : Controller
{
    [Route("/Logout")]
    public async Task<IActionResult> LogoutAsync()
    {
        await this.HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);

        return this.RedirectToPage(ApplicationConstants.IndexPage);
    }
}

In _Layout.cshtml file I have the following:

<a class="nav-link" asp-controller="Account" asp-action="LogoutAsync"><i class="fa fa-sign-out fa-lg" aria-hidden="true"></i></a>

In _ViewImports.cshtml file, which is in the parent directory of _Layout.cshtml , I have the following:

@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

In Startup.cs file, I added the following:

public void ConfigureServices(IServiceCollection services)
{
    // stuff

    services.AddControllers();

    services.AddRazorPages()
        .AddRazorPagesOptions(options =>
        {
            options.Conventions.AuthorizePage("/Page1");
            options.Conventions.AuthorizePage("/Page2");
        });

    // more stuff
}

public static void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // stuff

    app.UseAuthentication();

    app.UseRouting();

    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
        endpoints.MapRazorPages();
    });
}

Visual Studio seems to be happy with this setup and recognises asp-controller and asp-action as ASP.NET Core Tag Helpers.

However, when I run the application, the link is rendered as the following (notice the empty href ):

<a class="nav-link" href=""><i class="fa fa-sign-out fa-lg" aria-hidden="true"></i></a>

What am I missing?

Notes:

• I am upgrading the application from ASP.NET Core 2.2 to 3.1. It is working with 2.2.
• Yes, I searched Stack Overflow and googled the issue and reached no solution.

Answer 1

As far as I know, if you want to let the a tag generate the herf, you should set the route template in the Configure method.

More details, you could refer to below codes:

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Error");
        // 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.UseRouting();

    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllerRoute(
               name: "default",
               pattern: "{controller=Home}/{action=Index}/{id?}");

        endpoints.MapRazorPages();
    });
}

Result:

Answer 2

Looks like it is a known and intentional behaviour that was introduced in ASP.NET Core 3.0.

If the Action Method has Async suffix, it will be ignored; hence, asp-action will not see LogoutAsync as a valid Action.

For reference, see this documentation about migrating to ASP.NET Core 3.0 from 2.2 and this GitHub issue.