如何从 Asp.Net Core 的 ConfigureServices 方法内部访问添加到 DI 容器的服务

Question

下面的代码示例来自ConfigureServicesStartup.cs 中的Asp.Net Core方法。

我首先注册一个名为AppState. 之后，我正在配置 OpenIdConnect，并且在OnTokenValidatedlambda内部，我需要访问AppState我刚刚在上面的 DI 容器中注册的服务。

访问AppState服务实例的最优雅的方式是什么？

如果可能的话，我宁愿不在方法services.BuildServiceProvider()内部调用ConfigureServices。

services.AddSingleton<AppState>();

services.Configure<OpenIdConnectOptions>(AzureADB2CDefaults.OpenIdScheme, options =>
{
    options.Events = new OpenIdConnectEvents
    {
        OnTokenValidated = async ctx =>
        {
            //How to get access to instance of AppState, 
            //which was added to DI container up above
            AppState appState = //{get from DI somehow}; 
            appState.DoSomething();
        }
    };
});

编辑：使用下面的答案，我像这样编辑了代码，但我可以确认 OnTokenValidated 事件没有触发，而不是我原始问题中的上面的代码，它确实触发了：

services.AddOptions<OpenIdConnectOptions>(AzureADB2CDefaults.OpenIdScheme)
            .Configure<IServiceScopeFactory>((options, sp) => {
                using (var scope = sp.CreateScope())
                {
                    options.Events = new OpenIdConnectEvents
                    {
                        OnTokenValidated = async ctx =>
                        {
                            var appState = scope.ServiceProvider.GetRequiredService<AppState>();

                            await appState.Dosomething();         
                        }
                    };
                }
            });

Answer 1

使用TokenValidatedContext访问当前请求服务提供者并解析服务

services
    .Configure<OpenIdConnectOptions>(AzureADB2CDefaults.OpenIdScheme, options => {
        options.Events = new OpenIdConnectEvents {
            OnTokenValidated = async ctx => {
                //Get access to instance of AppState, 
                //which was added to DI container up above
                AppState appState = ctx.HttpContext.RequestServices
                    .GetRequiredService<AppState>();
                await appState.DoSomething();

                //...
            }
        };
    });