ASP.NET Core Dependency Injection inside Startup.Configure -

i using cookie middleware authenticate user. have been following this official tutorial.

inside startup class, excerpt configure method looks this:

public void configure(iapplicationbuilder app, ihostingenvironment env, iloggerfactory loggerfactory) {   // ...    // cookie-based authentication   app.usecookieauthentication(new cookieauthenticationoptions()   {     authenticationscheme = cookieauthenticationdefaults.authenticationscheme,             automaticauthenticate = true,     automaticchallenge = true,     events = new customcookieauthenticationevents(app),   });    // ... } 

the customcookieauthenticationevents class defined follows:

public class customcookieauthenticationevents : cookieauthenticationevents {   private iapplicationbuilder _app;   private imyservice _myservice = null;   private imyservice myservice   {         {       if(_myservice != null)       {         return _myservice;       } else       {         return _myservice = (imyservice) _app.applicationservices.getservice(typeof(imyservice));       }     }   }    public customcookieauthenticationevents(iapplicationbuilder app)   {     _app = app;   }    public override async task validateprincipal(cookievalidateprincipalcontext context)   {     string sessiontoken = context.principal.claims.firstordefault(x => x.type == claimtypes.sid)?.value;     logonsession response = null;      var response = await myservice.checksession(sessiontoken);      if (response == null)     {       context.rejectprincipal();       await context.httpcontext.authentication.signoutasync(cookieauthenticationdefaults.authenticationscheme);     }   } } 

since dependency injection not available @ startup.configure (the services not registered @ point), made bit of workaround:

1. pass iapplicationbuilder service customcookieauthenticationevents class
2. fetch imyservice upon first request inside read-only property (singleton pattern)

tl;dr

my solution works, it's ugly. there no dependency injection involved, not possible @ time.

the essence of problem must instantiate customcookieauthenticationevents. far have read source code, there no way around this, because usecookieauthentication throws exception if omit options parameter.

any suggestion how can 1 make current solution nicer?

startup.configureservices() called before startup.configure() (see https://docs.microsoft.com/en-us/aspnet/core/fundamentals/startup more information). dependency injection available @ time ;)
consequence, can resolve dependence in configure method this:

app.applicationservices.getrequiredservice<customcookieauthenticationevents>()