升级至.NET 7后ASP.NET Core MVC应用无法运行，求问题排查

我把ASP.NET MVC 2.2应用升级到ASP.NET Core 7 MVC后，应用无法正常运行。以下是我的startup.cs代码，麻烦帮我看看哪里出错了？

public IServiceProvider ConfigureServices(IServiceCollection services)
{ 
    services
          .AddAntiforgery(options => options.HeaderName = "XSRF-TOKEN")
          .AddControllers(options =>
          {
              options.CacheProfiles.Add("DefaultNoCacheProfile", new CacheProfile
              {
                  NoStore = true,
                  Location = ResponseCacheLocation.None
              });
              options.Filters.Add(new ResponseCacheAttribute
              {
                  CacheProfileName = "DefaultNoCacheProfile"
              });

    var sp = services.BuildServiceProvider(); 
    /* Here getting a Warning ASP0000 Calling 'BuildServiceProvider' 
       from application code results in an additional copy 
       of singleton services being created. 
       Consider alternatives such as dependency injecting 
       services as parameters to 'Configure' */

    return sp;
}

public void Configure(IApplicationBuilder app, IHostEnvironment env)
{
      // app.UseSession();
      
      app.UseAuthentication();

      if (env.IsDevelopment())
      {
          app.UseDeveloperExceptionPage();
      }
      else
      {
          app.UseExceptionHandler("/Home/Error");
      }

      app.UseMiddleware<HttpRequestWare>(_container);
      app.UseStaticFiles();

      app.UseCookiePolicy(new CookiePolicyOptions
      {
          MinimumSameSitePolicy = SameSiteMode.Strict,
      });

      var environment = _config["Environment"];

      if (environment == EnvironmentType.Live.ToString())
      {
          var supportedCultures = new[]
          {
              new CultureInfo("en-US")
          };
          app.UseRequestLocalization(new RequestLocalizationOptions
          {
              SupportedCultures = supportedCultures,
              SupportedUICultures = supportedCultures,
              RequestCultureProviders = new List<IRequestCultureProvider> {
                  new AcceptLanguageHeaderRequestCultureProvider()
              }
          });
      }

     //app.UseMvc();
      app.UseRouting();
      app.UseEndpoints(endpoints => {
          endpoints.MapDefaultControllerRoute();
          endpoints.MapControllerRoute("default", "{controller=Account}/{action=login}/{id?}");
          endpoints.MapControllerRoute("api", "{controller}/{action}/{id?}");
      });
}

收到的警告信息：

警告 ASP0000 从应用代码中调用‘BuildServiceProvider’会导致创建单例服务的额外副本。
请考虑替代方案，例如将服务作为参数依赖注入到‘Configure’中

主要问题及修复方案 #

1. 错误手动构建服务提供者 #

ASP.NET Core框架会自动处理服务容器的构建，不需要在ConfigureServices中手动调用BuildServiceProvider并返回IServiceProvider。这种写法会导致单例服务被实例化两次，触发ASP0000警告，还可能引发依赖注入逻辑混乱。

修复：
将ConfigureServices返回类型改为void，移除手动构建代码，同时补上原代码中缺失的AddControllers闭合大括号：

public void ConfigureServices(IServiceCollection services)
{ 
    services
          .AddAntiforgery(options => options.HeaderName = "XSRF-TOKEN")
          .AddControllers(options =>
          {
              options.CacheProfiles.Add("DefaultNoCacheProfile", new CacheProfile
              {
                  NoStore = true,
                  Location = ResponseCacheLocation.None
              });
              options.Filters.Add(new ResponseCacheAttribute
              {
                  CacheProfileName = "DefaultNoCacheProfile"
              });
          }); // 补上缺失的闭合大括号
}

2. 中间件顺序错误 #

ASP.NET Core中间件顺序直接决定请求处理流程，你的顺序存在多处问题：

• UseAuthentication必须放在UseRouting之后、UseEndpoints之前
• UseRequestLocalization应放在UseStaticFiles之前，确保本地化逻辑覆盖静态资源请求
• UseCookiePolicy需放在UseAuthentication之前

调整后的Configure方法：

public void Configure(IApplicationBuilder app, IHostEnvironment env, IConfiguration config)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
    }

    // 本地化中间件前置
    var environment = config["Environment"];
    if (environment == EnvironmentType.Live.ToString())
    {
        var supportedCultures = new[]
        {
            new CultureInfo("en-US")
        };
        app.UseRequestLocalization(new RequestLocalizationOptions
        {
            SupportedCultures = supportedCultures,
            SupportedUICultures = supportedCultures,
            RequestCultureProviders = new List<IRequestCultureProvider> {
                new AcceptLanguageHeaderRequestCultureProvider()
            }
        });
    }

    app.UseStaticFiles();
    app.UseCookiePolicy(new CookiePolicyOptions
    {
        MinimumSameSitePolicy = SameSiteMode.Strict,
    });

    app.UseRouting();
    // 认证中间件放在路由之后、端点之前
    app.UseAuthentication();
    // 若需授权，添加 app.UseAuthorization();

    app.UseMiddleware<HttpRequestWare>(_container);

    app.UseEndpoints(endpoints => {
        endpoints.MapControllerRoute("default", "{controller=Account}/{action=login}/{id?}");
        endpoints.MapControllerRoute("api", "{controller}/{action}/{id?}");
    });
}

3. 路由规则冲突 #

你同时添加了MapDefaultControllerRoute（默认指向Home/Index）和自定义default路由（指向Account/login），两个规则会冲突，建议只保留符合业务需求的一个。

4. 未正确注入依赖 #

_config和_container需要通过构造函数注入到Startup类，不能直接使用：

private readonly IConfiguration _config;
private readonly IServiceProvider _container;

public Startup(IConfiguration config, IServiceProvider container)
{
    _config = config;
    _container = container;
}

5. 会话功能（若需启用） #

如果应用需要会话，需先在ConfigureServices中添加services.AddSession();，再在Configure中把app.UseSession()放在UseRouting之前、UseStaticFiles之后。

内容的提问来源于stack exchange，提问作者Ertugul