I am developing a web application with a REST API using C# with ASP.NET Core 2.0.

What I want to achieve is when the client send a request to an endpoint I will run a background task separated from the client request context which will be ended if the task started successfully.

I know there is `HostedService` but the problem is that the `HostedService` starts when the server starts, and as far as I know there is no way to start the `HostedService` manually from a controller.

Here is a simple code that demonstrates the question.
```
[Authorize(AuthenticationSchemes = &quot;UsersScheme&quot;)]
public class UsersController : Controller
{
    [HttpPost]
    public async Task&lt;JsonResult&gt; StartJob([FromForm] string UserId, [FromServices] IBackgroundJobService backgroundService)
    {
        // check user account
        (bool isStarted, string data) result = backgroundService.Start();

        return JsonResult(result);
    }
}
```

Run a background task from a controller action in ASP.NET Core

After reading Microsoft documents I am still confused. I need to deploy a .net core 2 web application I developed to an IIS server and I can&#39;t get a straight forward answer on anything. This is just the beginning of my questions.

What is the difference between IWebHost, WebHostBuilder, BuildWebHost?

Thanks!

What is the difference between IWebHost WebHostBuilder BuildWebHost

I am having a few issues with EF Core at the moment. I have some data that I need to delete, and I am struggeling to see how the fluent API works, exactly in regards to the `.OnDelete()` function.

Considering the classic blog/post scenario from [microsofts own websites][1], I wonder what entity, exactly the `OnDelete()` is &#39;targeting&#39; (for the lack of a better word) In some instances it seems to be the blog, in others, the post. Can the Cascade delete be defined from both sides (that the posts are deleted when the parent Blog is) if so i imagine the code should look like this:

`model.Entity&lt;Post&gt;().HasOne(p =&gt; p.Blog).WithMany(b =&gt; b.Posts).HasForeignKey(p =&gt; p.BlogId).OnDelete(DeleteBehavior.Cascade)`

As i understand this is saying &quot;When a Blog is deleted, first delete all posts referencing this blog&quot; meaning the `OnDelete(DeleteBehavior.Cascade)`applies to blog, not to post.

But is this the same then?

`model.Entity&lt;Blog&gt;().HasMany(b =&gt; b.Posts).WithOne(p =&gt; p.Blog).OnDelete(DeleteBehavior.Cascade)`

or does `OnDelete(DeleteBehavior.Cascade)` apply to Post rather than blog?


  [1]: https://docs.microsoft.com/en-us/ef/core/saving/cascade-delete

Cascade deleting with EF Core

I&#39;m trying to migrate my auth stuff to Core 2.0 and having an issue using my own authentication scheme. My service setup in startup looks like this:

    var authenticationBuilder = services.AddAuthentication(options =&gt;
    {
    	options.AddScheme(&quot;myauth&quot;, builder =&gt;
    	{
    		builder.HandlerType = typeof(CookieAuthenticationHandler);
    	});
    })
    	.AddCookie();

My login code in the controller looks like this:

    var claims = new List&lt;Claim&gt;
    {
    	new Claim(ClaimTypes.Name, user.Name)
    };
    
    var props = new AuthenticationProperties
    {
    	IsPersistent = persistCookie,
    	ExpiresUtc = DateTime.UtcNow.AddYears(1)
    };
    
    var id = new ClaimsIdentity(claims);
    await HttpContext.SignInAsync(&quot;myauth&quot;, new ClaimsPrincipal(id), props);

But when I&#39;m in a controller or action filter, I only have one identity, and it&#39;s not an authenticated one:

    var identity = context.HttpContext.User.Identities.SingleOrDefault(x =&gt; x.AuthenticationType == &quot;myauth&quot;);

Navigating these changes has been difficult, but I&#39;m guessing that I&#39;m doing .AddScheme wrong. Any suggestions?

EDIT: Here&#39;s (essentially) a clean app that results not in two sets of Identities on User.Identies:

    namespace WebApplication1.Controllers
    {
        public class Testy : Controller
        {
    	    public IActionResult Index()
    	    {
    		    var i = HttpContext.User.Identities;
    		    return Content(&quot;index&quot;);
    	    }
    
    	    public async Task&lt;IActionResult&gt; In1()
    	    {
    			var claims = new List&lt;Claim&gt; { new Claim(ClaimTypes.Name, &quot;In1 name&quot;) };
    		    var props = new AuthenticationProperties  { IsPersistent = true, ExpiresUtc = DateTime.UtcNow.AddYears(1) };
    		    var id = new ClaimsIdentity(claims);
    		    await HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, new ClaimsPrincipal(id), props);
    		    return Content(&quot;In1&quot;);
    		}
    
    	    public async Task&lt;IActionResult&gt; In2()
    	    {
    		    var claims = new List&lt;Claim&gt; { new Claim(ClaimTypes.Name, &quot;a2 name&quot;) };
    		    var props = new AuthenticationProperties { IsPersistent = true, ExpiresUtc = DateTime.UtcNow.AddYears(1) };
    		    var id = new ClaimsIdentity(claims);
    		    await HttpContext.SignInAsync(&quot;a2&quot;, new ClaimsPrincipal(id), props);
    		    return Content(&quot;In2&quot;);
    	    }
    
    	    public async Task&lt;IActionResult&gt; Out1()
    	    {
    		    await HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
    		    return Content(&quot;Out1&quot;);
    		}
    
    	    public async Task&lt;IActionResult&gt; Out2()
    	    {
    		    await HttpContext.SignOutAsync(&quot;a2&quot;);
    		    return Content(&quot;Out2&quot;);
    	    }
    	}
    }

And Startup:

    namespace WebApplication1
    {
        public class Startup
        {
            public Startup(IConfiguration configuration)
            {
                Configuration = configuration;
            }
    
            public IConfiguration Configuration { get; }
    		
            public void ConfigureServices(IServiceCollection services)
            {
    			services.AddAuthentication(options =&gt;
    			{
    				options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
    		        })
    		        .AddCookie(CookieAuthenticationDefaults.AuthenticationScheme)
    		        .AddCookie(&quot;a2&quot;);
    
    			services.AddMvc();
            }
    		
            public void Configure(IApplicationBuilder app, IHostingEnvironment env)
            {
                app.UseAuthentication();
    
                app.UseMvc(routes =&gt;
                {
                    routes.MapRoute(name: &quot;default&quot;, template: &quot;{controller=Home}/{action=Index}/{id?}&quot;);
                });
            }
        }
    }




How do I setup multiple auth schemes in ASP.NET Core 2.0?

I have a question regarding authentication in ASP.NET Core 2: what exactly is the call **app.UseAuthentication()** for? 

Is it a basic prerequisite so that I can implement my custom authentication logic? I already had a look at the implementation of [UseAuthentication][1] and also of the actual middleware [AuthenticationMiddleware][2], but to be honest, I don&#39;t understand what that is actually doing and why it would be necessary. 

To put it in another way: 

Do I need to call **UseAuthentication()**
[![enter image description here][3]][3]

or is it a nice-to-have and I can do my custom auth anyways?
[![enter image description here][4]][4]

If I was fine without calling **UseAuthentication()** I&#39;d still be interested in what [AuthenticationMiddleware][2] is actually doing. So if you knew that I&#39;d be very grateful if you could explain it for me as well. 



  [1]: https://github.com/aspnet/Security/blob/dev/src/Microsoft.AspNetCore.Authentication/AuthAppBuilderExtensions.cs
  [2]: https://github.com/aspnet/Security/blob/1c30f33c925a97b105b3f9d34497218b0c9342b6/src/Microsoft.AspNetCore.Authentication/AuthenticationMiddleware.cs
  [3]: https://i.stack.imgur.com/MYmlo.png
  [4]: https://i.stack.imgur.com/BhaxK.png

What exactly is &#39;UseAuthentication()&#39; for?

The new .csproj format includes some significant improvements over the classic files, including tight integration with NuGet package management and significantly less-verbose structure. I want to gain these benefits whilst still using the .NET Framework 4.6 and ASP.NET (because my project depends on Umbraco which has yet to produce a .NET Core version).

The biggest challenge would seem to be the debugging experience - an ASP.NET Core project expects to run a dotnet core application and set up a reverse proxy to an IIS instance. This process is completely alien to the .NET Framework model and I wouldn&#39;t know where to start trying to set up debugging in Visual Studio.

Is there any way to get these two project models to mix?

Can the new csproj file structure be used with a ASP.NET Framework project?

When I try to run my app I get the error 

    InvalidOperationException: Cannot resolve &#39;API.Domain.Data.Repositories.IEmailRepository&#39; from root provider because it requires scoped service &#39;API.Domain.Data.EmailRouterContext&#39;.

What&#39;s odd is that this EmailRepository and interface is set up exactly the same as far as I can tell as all of my other repositories yet no error is thrown for them.  The error only occurs if I try to use the app.UseEmailingExceptionHandling(); line. Here&#39;s some of my Startup.cs file.


    public class Startup
    {
        public IConfiguration Configuration { get; protected set; }
        private APIEnvironment _environment { get; set; }
    
        public Startup(IConfiguration configuration, IHostingEnvironment env)
        {
            Configuration = configuration;
    
            _environment = APIEnvironment.Development;
            if (env.IsProduction()) _environment = APIEnvironment.Production;
            if (env.IsStaging()) _environment = APIEnvironment.Staging;
        }
    
        public void ConfigureServices(IServiceCollection services)
        {
            var dataConnect = new DataConnect(_environment);
    
            services.AddDbContext&lt;GeneralInfoContext&gt;(opt =&gt; opt.UseSqlServer(dataConnect.GetConnectString(Database.GeneralInfo)));
            services.AddDbContext&lt;EmailRouterContext&gt;(opt =&gt; opt.UseSqlServer(dataConnect.GetConnectString(Database.EmailRouter)));
    
            services.AddWebEncoders();
            services.AddMvc();
    
            services.AddScoped&lt;IGenInfoNoteRepository, GenInfoNoteRepository&gt;();
            services.AddScoped&lt;IEventLogRepository, EventLogRepository&gt;();
            services.AddScoped&lt;IStateRepository, StateRepository&gt;();
            services.AddScoped&lt;IEmailRepository, EmailRepository&gt;();
        }
    
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole();
    
            app.UseAuthentication();
    
            app.UseStatusCodePages();
            app.UseEmailingExceptionHandling();
    
            app.UseMvcWithDefaultRoute();
        }
    }

Here is the EmailRepository

    public interface IEmailRepository
    {
        void SendEmail(Email email);
    }
    
    public class EmailRepository : IEmailRepository, IDisposable
    {
        private bool disposed;
        private readonly EmailRouterContext edc;
    
        public EmailRepository(EmailRouterContext emailRouterContext)
        {
            edc = emailRouterContext;
        }
    
        public void SendEmail(Email email)
        {
            edc.EmailMessages.Add(new EmailMessages
            {
                DateAdded = DateTime.Now,
                FromAddress = email.FromAddress,
                MailFormat = email.Format,
                MessageBody = email.Body,
                SubjectLine = email.Subject,
                ToAddress = email.ToAddress
            });
            edc.SaveChanges();
        }
    
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }
    
        private void Dispose(bool disposing)
        {
            if (!disposed)
            {
                if (disposing)
                    edc.Dispose();
                disposed = true;
            }
        }
    }

And finally the exception handling middleware

    public class ExceptionHandlingMiddleware
    {
        private const string ErrorEmailAddress = &quot;errors@ourdomain.com&quot;;
        private readonly IEmailRepository _emailRepository;
    
        private readonly RequestDelegate _next;
    
        public ExceptionHandlingMiddleware(RequestDelegate next, IEmailRepository emailRepository)
        {
            _next = next;
            _emailRepository = emailRepository;
        }
    
        public async Task Invoke(HttpContext context)
        {
            try
            {
                await _next.Invoke(context);
            }
            catch (Exception ex)
            {
                await HandleExceptionAsync(context, ex, _emailRepository);
            }
        }
    
        private static Task HandleExceptionAsync(HttpContext context, Exception exception,
            IEmailRepository emailRepository)
        {
            var code = HttpStatusCode.InternalServerError; // 500 if unexpected
    
            var email = new Email
            {
                Body = exception.Message,
                FromAddress = ErrorEmailAddress,
                Subject = &quot;API Error&quot;,
                ToAddress = ErrorEmailAddress
            };
    
            emailRepository.SendEmail(email);
    
            context.Response.ContentType = &quot;application/json&quot;;
            context.Response.StatusCode = (int) code;
            return context.Response.WriteAsync(&quot;An error occured.&quot;);
        }
    }
    
    public static class AppErrorHandlingExtensions
    {
        public static IApplicationBuilder UseEmailingExceptionHandling(this IApplicationBuilder app)
        {
            if (app == null)
                throw new ArgumentNullException(nameof(app));
            return app.UseMiddleware&lt;ExceptionHandlingMiddleware&gt;();
        }
    }

Update:
I found this link https://github.com/aspnet/DependencyInjection/issues/578 which led me to change my Program.cs file&#39;s BuildWebHost method from this

    public static IWebHost BuildWebHost(string[] args)
    {
        return WebHost.CreateDefaultBuilder(args)
            .UseStartup&lt;Startup&gt;()
            .Build();
    }

to this

    public static IWebHost BuildWebHost(string[] args)
    {
        return WebHost.CreateDefaultBuilder(args)
            .UseStartup&lt;Startup&gt;()
            .UseDefaultServiceProvider(options =&gt;
                options.ValidateScopes = false)
            .Build();
    }

I don&#39;t know what exactly is going on but it seems to work now.

Cannot resolve scoped service from root provider .Net Core 2

Is it possible to support multiple JWT Token issuers in ASP.NET Core 2?
I want to provide an API for external service and I need to use two sources of JWT tokens - Firebase and custom JWT token issuers. In ASP.NET core I can set the JWT authentication for Bearer auth scheme, but only for one Authority:
  

      services
            .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
            .AddJwtBearer(options =&gt;
            {
                options.Authority = &quot;https://securetoken.google.com/my-firebase-project&quot;
                options.TokenValidationParameters = new TokenValidationParameters
                    {
                        ValidateIssuer = true,
                        ValidIssuer = &quot;my-firebase-project&quot;
                        ValidateAudience = true,
                        ValidAudience = &quot;my-firebase-project&quot;
                        ValidateLifetime = true
                    };
            }

I can have multiple issuers and audiences, but I can&#39;t set several Authorities.


Use multiple JWT Bearer Authentication

I want to update Bootstrap in ASP.NET Core with NuGet. I used this:

    Install-Package bootstrap -Version 4.0.0

It did add the dependencies but how do I add it to my project now? What is the path for local NuGet dependencies?

![Installed NuGet dependencies](https://i.stack.imgur.com/J7fL6.png)

How to use Bootstrap 4 in ASP.NET Core

After upgrading to ASP.NET Core 2.0, I can&#39;t seem to create migrations anymore.

I&#39;m getting 

&gt; &quot;An error occurred while calling method &#39;BuildWebHost&#39; on class
&gt; &#39;Program&#39;. Continuing without the application service provider. Error:
&gt; One or more errors occurred. (Cannot open database &quot;...&quot; requested by
&gt; the login. The login failed. Login failed for user &#39;...&#39;&quot;

and

&gt; &quot;Unable to create an object of type &#39;MyContext&#39;. Add an implementation
&gt; of &#39;IDesignTimeDbContextFactory&lt;MyContext&gt;&#39; to the project, or see
&gt; https://go.microsoft.com/fwlink/?linkid=851728 for additional patterns
&gt; supported at design time.&quot;

The command I previously ran was `$ dotnet ef migrations add InitialCreate --startup-project &quot;..\Web&quot; ` (from the project/folder with the DBContext).

Connection string: `&quot;Server=(localdb)\\mssqllocaldb;Database=database;Trusted_Connection=True;MultipleActiveResultSets=true&quot;`


This is my Program.cs

     public class Program
    {
        public static void Main(string[] args)
        {
            BuildWebHost(args).Run();
        }

        public static IWebHost BuildWebHost(string[] args) =&gt;
           WebHost.CreateDefaultBuilder(args)
               .UseStartup&lt;Startup&gt;()
               .Build();
    }
 


Unable to create migrations after upgrading to ASP.NET Core 2.0

With Core 1.1 followed @blowdart&#39;s advice and implemented a custom middleware:

https://stackoverflow.com/a/31465227/29821

It worked like this:

1. Middleware ran. Picked up a token from the request headers.
2. Verified the token and if valid built an identity (ClaimsIdentity) that contained multiple claims which then it added via HttpContext.User.AddIdentity();
3. In ConfigureServices using services.AddAuthorization I&#39;ve added a policy to require the claim that is provided by the middleware.
4. In the controllers/actions I would then use [Authorize(Roles = &quot;some role that the middleware added&quot;)]

This somewhat works with 2.0, except that if the token is not valid (step 2 above) and the claim is never added I get &quot;No authenticationScheme was specified, and there was no DefaultChallengeScheme found.&quot;

So now I&#39;m reading that auth changed in 2.0:

https://docs.microsoft.com/en-us/aspnet/core/migration/1x-to-2x/identity-2x

What&#39;s the right path for me to do the same thing in ASP.NET Core 2.0? I don&#39;t see an example to do truly custom authentication.

ASP.NET Core 2.0 authentication middleware

I have a .NET Core 2.0 app and have a problem with authorization. I want to use custom authorization with special requests. Header and standard default authentication.
First, I add configuration in `Startup.cs`:

    public IServiceProvider ConfigureServices(IServiceCollection services)
    {
        // ...
        services.AddAuthorization(options =&gt;
    	{
    		options.AddPolicy(DefaultAuthorizedPolicy, policy =&gt;
    		{
    			policy.Requirements.Add(new TokenAuthRequirement());
    		});
    	});
        services.AddSingleton&lt;IAuthorizationHandler, AuthTokenPolicy&gt;();
        // ...
    }

`AuthTokenPolicy.cs`:

    public class AuthTokenPolicy : AuthorizationHandler&lt;TokenAuthRequirement&gt;
	{	
		protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, TokenAuthRequirement requirement)
		{
			var filterContext = context.Resource as AuthorizationFilterContext;
			var response = filterContext.HttpContext.Response;
			try
			{
				// some validation code

				var isValidToken = isValidTokenTask.Result;
				if (!isValidToken)
				{
					response.StatusCode = 401;
					return Task.CompletedTask;
				}

				response.StatusCode = 200;
				context.Succeed(requirement);
			}
			catch (Exception)
			{
				return Task.CompletedTask;
			}
			return Task.CompletedTask;
		}
	}
and in `HomeController.cs`:

    [Authorize(Policy = Startup.DefaultAuthorizedPolicy)]
    public async Task&lt;IActionResult&gt; IsVisible()

If I use the wrong request.header in `AuthTokenPolicy` I see it, but in the logs I see this error:

&gt; System.InvalidOperationException: No authenticationScheme was specified, and there was no DefaultChallengeScheme found.\r\n   at Microsoft.AspNetCore.Authentication.AuthenticationService.&lt;ChallengeAsync&gt;d__11.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Mvc.ChallengeResult.&lt;ExecuteResultAsync&gt;d__14.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.&lt;InvokeResultAsync&gt;d__19.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.&lt;InvokeFilterPipelineAsync&gt;d__17.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.&lt;InvokeAsync&gt;d__15.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Builder.RouterMiddleware.&lt;Invoke&gt;d__4.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.&lt;Invoke&gt;d__3.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at React.AspNet.BabelFileMiddleware.&lt;Invoke&gt;d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.&lt;Invoke&gt;d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at core.common.Middleware.LoggingMiddleware.&lt;Invoke&gt;d__3.MoveNext() in D:\\Dev\\microservicePDP\\Template\\core.common\\Middleware\\LoggingMiddleware.cs:line 72

After reading [Migrating Authentication and Identity to ASP.NET Core 2.0][1] I&#39;ve added this code in startup.cs


  [1]: https://docs.microsoft.com/en-us/aspnet/core/migration/1x-to-2x/identity-2x
Quotation from the article : 

    services.AddAuthentication(options =&gt; 
    {
        options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
    });

&gt; Define a default scheme in 2.0 if one of the following conditions is true:
You want the user to be automatically signed in
You use the [Authorize] attribute or authorization policies without specifying schemes

I added `AuthenticationScheme` and `DefaultChallengeScheme` in `ConfigureServices()`. It didn&#39;t help, the same error here. I&#39;ve tried to use `app.UseAuthentication();` in the `Startup.Configure()` method, with no results.

How can I use a custom authorization without authentication?

No authenticationScheme was specified, and there was no DefaultChallengeScheme found with default authentification and custom authorization

I have installed `ASP.NET Core 2.1` but even though I have created a new `ASP.NET Core Web Application` using `ASP.NET Core 2.1` with `Individual User Accounts` → `Store user accounts in-app` I can&#39;t find the AccountController or Views. 

I can still register and login without a problem but I can&#39;t find the code for it, it were present in 2.0. 

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/1TB6a.png

Identity in ASP.Net Core 2.1&lt; - Customize AccountController

**How can I call SignalR Core Hub method from Controller?**  
I am using  ASP.NET Core 2.0 with Microsoft.AspNetCore.SignalR (1.0.0-alpha2-final).

I have windows service which communicate with Excel, SolidEdge ... When operation is complete it post request to my controller in ASP.NET Core application. Now I need to inform all clients connected to server with SignalR that external program completed some task.  
I can not change the way window service works. (Can not connect to SignalR from window service).  
I found plenty solution for old SignalR (`GlobalHost.ConnectionManager.GetHubContext`), but much has changed and those solutions are not working anymore.

My controller:

    [Route(&quot;API/vardesigncomm&quot;)]
    public class VarDesignCommController : Controller
    {
        [HttpPut(&quot;ProcessVarDesignCommResponse/{id}&quot;)]
        public async Task&lt;IActionResult&gt; ProcessVarDesignCommResponse(int id)
        {
            //call method TaskCompleted in Hub !!!! How?
     
            return new JsonResult(true);
        }
    }

My hub:

    public class VarDesignHub : Hub
    {
        public async Task TaskCompleted(int id)
        {
            await Clients.All.InvokeAsync(&quot;Completed&quot;, id);
        }
    }




Call SignalR Core Hub method from Controller

For Asp.net Core apps, which one do we have to use? `AddDbContext` or `AddDbContextPool`? According to EF Core documentation, `AddDbContextPool` provides high performance but the default Asp.net Core project templates use `AddDbContext`. 




AddDbContext or AddDbContextPool

ASP.NET Core 2.1.1 offers several seemingly related extension methods for appBuilder:

* `UseStaticFiles` from `Microsoft.AspNetCore.StaticFiles`
* `UseSpaStaticFiles` from `Microsoft.AspNetCore.SpaServices.Extensions`
* `UseSpa` from `Microsoft.AspNetCore.SpaServices.Extensions`

**Please help me make sense of their purpose and relation to each other?**

Also, is there any difference from the server execution standpoint if I run these methods in a different order 

e.g. 

    app.UseStaticFiles() -&gt; app.UseSpaStaticFiles() -&gt; app.UseSpa()

vs 

    app.UseSpa() -&gt; app.UseSpaStaticFiles() -&gt; app.UseStaticFiles()

What is the difference between UseStaticFiles, UseSpaStaticFiles, and UseSpa in ASP.NET Core 2.1?

This question is because in my MVC project with **ASP.NET CORE 2.0**, I can not add the `[FromUri] attribute` to my drivers.

I tried using libraries like `System.Web.Http`, but I did not recognize them. Then install these from Nuget `Microsoft.AspNet.WebApi.Core` &quot;and&quot; `System.AppDomain.NetCoreApp`, which resulted in being able to use `System.Web.Http` but due to ambiguity problems I was not allowed to use it, but if I found that `[FromUri]` existed.


The main question is whether in ASP.NET core 2.0 MVC or WebApi exists `[FromUri]` ?

if it exists, how to use it?

FromUri in ASP.NET CORE 2.0

I am trying to inject dependency into my middleware constructor as follows

    public class CreateCompanyMiddleware
	{
	    private readonly RequestDelegate _next;
	    private readonly UserManager&lt;ApplicationUser&gt; _userManager;

	    public CreateCompanyMiddleware(RequestDelegate next
	        , UserManager&lt;ApplicationUser&gt; userManager
	        )
	    {
	        _next = next;
	    }

	    public async Task Invoke(HttpContext context)
	    {
	        await _next.Invoke(context);
	    }
	}

My Startup.cs file looks like

	public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext&lt;ApplicationDbContext&gt;(options =&gt;
            options.UseMySql(Configuration.GetConnectionString(&quot;IdentityConnection&quot;)));

        services.AddIdentity&lt;ApplicationUser, IdentityRole&gt;()
            .AddEntityFrameworkStores&lt;ApplicationDbContext&gt;()
            .AddDefaultTokenProviders();
        ...

        app.UseMiddleware&lt;CreateCompanyMiddleware&gt;();

        ...

But I am getting this error

&gt; An error occurred while starting the application.
InvalidOperationException: Cannot resolve scoped service &#39;Microsoft.AspNetCore.Identity.UserManager`1[Common.Models.ApplicationUser]&#39; from root provider.
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope)

How to do DI in asp.net core middleware?

I am trying to use HttpClient in my .net core 2.0 project and for that I have injected HttpClient in my controller. But when I am trying to configure httpclient in my startup.cs I am getting this error: &quot;IServiceCollection does not contain a defintion for AddHttpClient&quot;. I have already referenced `using Microsoft.AspNetCore.Http;` and `using Microsoft.Extensions.DependencyInjection;` and here is what I am trying to do: 

    services.AddHttpClient&lt;TestController&gt;();

It&#39;s working fine in other project with same namespaces but here I am getting the error. Any help?

IServiceCollection does not contain a defintion for AddHttpClient

I worked on a asp.net core 1.1 project a while ago and use in projetc AutoMapper.

in asp.net core 1.1, I add `services.AddAutoMapper()` in startup file :

**StartUp file in asp.net core 1.1:**

        public void ConfigureServices(IServiceCollection services)
        {
            //Some Code

            services.AddMvc();
            services.AddAutoMapper();
        }

And I use AutoMapper in Controller easily.

**Controller :**

     public async Task&lt;IActionResult&gt; AddEditBook(AddEditBookViewModel model)
     {
        Book bookmodel = AutoMapper.Mapper.Map&lt;AddEditBookViewModel, Book&gt;(model);
        context.books.Add(bookmodel);
        context.SaveChanges();
     }
And everything was fine.
But I&#39;m currently working on a Asp.net Core 2 project and I get the error with `services.AddAutoMapper()` in sturtap file.

&gt; Error	CS0121	The call is ambiguous between the following methods or properties: &#39;ServiceCollectionExtensions.AddAutoMapper(IServiceCollection, params Assembly[])&#39; and &#39;ServiceCollectionExtensions.AddAutoMapper(IServiceCollection, params Type[])&#39;

What is the reason for this error?
Also, `services.AddAutoMapper` in asp.net core 2 has some parameters. what should I send to this parameter?

Trying to add AutoMapper to Asp.net Core 2?

I configure `log4net` in my asp.net core 2.0 application as mentioned in this article [LINK](https://stackify.com/making-log4net-net-core-work/) 

 program.cs

    public static void Main(string[] args)
    {
        var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly());
        XmlConfigurator.Configure(logRepository, new FileInfo(&quot;log4net.config&quot;));

        BuildWebHost(args).Run();
    }

HomeController

   

    public class HomeController : Controller
    {
        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(typeof(HomeController));
    
        public IActionResult Error()
        {
            log.Info(&quot;Hello logging world!&quot;);
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }

log4net.config 

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;configuration&gt;
      &lt;log4net&gt;
        &lt;root&gt;
          &lt;level value=&quot;ALL&quot; /&gt;
          &lt;appender-ref ref=&quot;RollingFile&quot; /&gt;
        &lt;/root&gt;
        &lt;appender name=&quot;RollingFile&quot; type=&quot;log4net.Appender.FileAppender&quot;&gt;
          &lt;file value=&quot;‪C:\Temp\app.log&quot; /&gt; 
          &lt;layout type=&quot;log4net.Layout.PatternLayout&quot;&gt;
            &lt;conversionPattern value=&quot;%-5p %d{hh:mm:ss} %message%newline&quot; /&gt;
          &lt;/layout&gt;
        &lt;/appender&gt;
      &lt;/log4net&gt;
    &lt;/configuration&gt;

Unlucky!, I didn&#39;t see any file generated in ‪`C:\Temp\app.log` directory. What would be the mistake? how to configure `log4net` for asp.net core 2.0? 

How to use log4net in Asp.net core 2.0

I am currently using ASP.NET Core 2.x and I used to be able to get Kestrel to to use HTTPS / SSL by simply putting it in the `UseUrls()` method like so:

    var host = new WebHostBuilder()
        .UseUrls(&quot;http://localhost&quot;, &quot;https://111.111.111.111&quot;)
        .UseKestrel()
        .Build();

But now I get the exception: 

     System.InvalidOperationException:
         HTTPS endpoints can only be configured using KestrelServerOptions.Listen().

---------

&gt; **How do I configure Kestrel to use SSL in ASP.NET Core 2.x?**

How to use HTTPS / SSL with Kestrel in ASP.NET Core 2.x?

I&#39;m new to ASP.NET Core and docker.
I&#39;ve created a simple ASP.NET Core 2.0 app and try to use docker with it on Windows. However, I get this error: 

`Your Docker server host is configured for &#39;Linux&#39;, however the docker-compose project targets &#39;Windows&#39;.`

Although it seems to be pretty informative error, I can&#39;t find where to &#39;configure host for Windows&#39;

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