为什么.netcore 3.1中找不到WebApi授权服务？

Question

我正在 .netcore 3.1 中创建一个 webapi 项目，这是我在 program.cs 中的代码

public class Program
{
    public static void Main(string[] args)
    {
        CreateHostBuilder(args).Build().Run();
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            });
}

这是我的startup.cs：

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public async Task ConfigureServices(IServiceCollection services)
    {
        services.AddAuthorization();

        services.RegisterEasyNetQ("host=localhost;username=admin;password=admin");
        services.AddSingleton(typeof(CreateOrderHandler));
        services.AddControllers();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseHttpsRedirection();

        app.UseRouting();

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

但运行该项目后我收到此异常：

应用程序启动异常System.InvalidOperationException：无法找到所需的服务。请通过在应用程序启动代码中调用“ConfigureServices(...)”内调用“IServiceCollection.AddAuthorization”来添加所有必需的服务。在Microsoft.AspNetCore.Builder.AuthorizationAppBuilderExtensions.VerifyServicesRegistered（IApplicationBuilder应用程序）在Microsoft.AspNetCore.Builder.AuthorizationAppBuilderExtensions.UseAuthorization（IApplicationBuilder应用程序）在project.Order.Startup.Configure（IApplicationBuilder应用程序，IWebHostEnvironment env）在/82a891c3-0533-4937 -9b8d-44d0c7405e9f/Roaming/project/project.Order/Startup.cs：System.RuntimeMethodHandle.InvokeMethod（对象目标，Object []参数，签名sig，布尔构造函数，布尔wrapExceptions）处的System.Reflection.RuntimeMethodInfo处的第50行。
在 Microsoft.AspNetCore.Hosting.ConfigureBuilder.Invoke(Object 实例、IApplicationBuilder 构建器) 在 Microsoft.AspNetCore.Hosting.ConfigureBuilder.<>c__DisplayClass4_0.b__0 调用（Object obj、BindingFlags invokeAttr、Binder binder、Object[] 参数、CultureInfo Culture ）(IApplicationBuilder 构建器) 在 Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.<>c__DisplayClass13_0.b__2(IApplicationBuilder 应用程序) 在 Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.b__0(IApplicationBuilder 应用程序) 在 Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancelToken) 未处理的异常。System.InvalidOperationException：无法找到所需的服务。请通过在应用程序启动代码中调用“ConfigureServices(...)”内调用“IServiceCollection.AddAuthorization”来添加所有必需的服务

我搜索了很多但找不到任何提示。

Answer 1

public async Task ConfigureServices(IServiceCollection services)

该ConfigureServies方法预计不会返回Task. 这意味着 ASP.NET Core 框架无法找到ConfigureServices您添加的这个特定方法。

更新签名，如下：

public void ConfigureServices(IServiceCollection services)

通过此更改，ConfigureServices将调用该方法，这将按预期添加服务。