.NET 7中ASP.NET Core授权失败未跳转登录页反而返回404

1. 检查Identity区域路由配置 #

确认Areas/Identity/IdentityHostingStartup.cs中正确配置了区域路由，保证区域路由优先匹配：

public class IdentityHostingStartup : IHostingStartup
{
    public void Configure(IWebHostBuilder builder)
    {
        builder.ConfigureServices((context, services) => {
            // 保留原有Identity服务配置
        });
        builder.Configure(app => {
            app.UseRouting();
            app.UseAuthentication();
            app.UseAuthorization();
            
            app.UseEndpoints(endpoints =>
            {
                // 配置区域路由规则
                endpoints.MapControllerRoute(
                  name: "areas",
                  pattern: "{area:exists}/{controller=Home}/{action=Index}/{id?}"
                );
                endpoints.MapDefaultControllerRoute();
                endpoints.MapRazorPages(); // 必须添加，Identity基于Razor Pages
            });
        });
    }
}

2. 修正Cookie认证的LoginPath配置 #

在Program.cs中，确保Cookie认证的LoginPath指向带区域的完整路径，并且和Identity默认认证方案关联：

// 方式1：单独配置Cookie认证
builder.Services.AddAuthentication(IdentityConstants.ApplicationScheme)
    .AddCookie(IdentityConstants.ApplicationScheme, options =>
    {
        options.LoginPath = "/Identity/Account/Login";
        options.LogoutPath = "/Identity/Account/Logout";
    });

// 方式2：通过AddIdentity配置Cookie选项
builder.Services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultTokenProviders()
    .AddDefaultUI()
    .AddCookieAuthentication(options =>
    {
        options.LoginPath = "/Identity/Account/Login";
    });

3. 确认Identity页面路由正确性 #

如果是Scaffold生成的Identity登录页，检查Areas/Identity/Pages/Account/Login.cshtml.cs的路由属性，确保没有错误的自定义路由：

[AllowAnonymous]
public class LoginModel : PageModel
{
    // 页面默认路由即为/Identity/Account/Login，无需额外修改
    // 业务逻辑代码...
}

4. 调整全局路由顺序 #

在Program.cs的端点配置中，优先注册Identity区域的专属路由，避免被默认路由覆盖：

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

app.UseEndpoints(endpoints =>
{
    // 先注册Identity区域路由
    endpoints.MapAreaControllerRoute(
        name: "Identity",
        areaName: "Identity",
        pattern: "Identity/{controller=Account}/{action=Login}/{id?}"
    );
    // 再注册默认控制器路由
    endpoints.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}"
    );
    endpoints.MapRazorPages();
});

5. 清除浏览器缓存与Cookie #

浏览器可能缓存旧的认证跳转规则，清除后重新测试验证。

内容的提问来源于stack exchange，提问作者Jeffry322