Develop Reference

Assistance converting .NET 5 into .NET 6

I am trying to seed my database and add roles to my ASP.NET Core Web Application. In the tutorial I am following, it advised to add the following to the Configure() method:
app.UseAuthentication();
MyIdentityDataInitializer.SeedData(userManager, roleManager);
I had no issues with the first line, but with the second, I am getting an error saying userManager and roleManager doesn't exist which makes sense because if i were using .NET 5 my configure method would've looked like this and been fine:
public void Configure(IApplicationBuilder app,
IHostingEnvironment env,
UserManager<MyIdentityUser> userManager,
RoleManager<MyIdentityRole> roleManager)
{
...
app.UseAuthentication();
MyIdentityDataInitializer.SeedData(userManager, roleManager);
app.UseStaticFiles();
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
}
But in .NET 6 I'm not sure how to.
Can someone advise on this please?

In .NET 6, Microsoft has removed the Startup.cs class where your Configure() method was previously defined. Instead, configuration of both the DI service container (which was done previously in the ConfigureServices(IServiceCollection)) method) and the AspNet Core Application Builder are done directly in Program.cs
Now since there is nothing automatically calling the Configure() method for you (and injecting those values for you), you'll have to get references to those objects yourself using the ServiceProvider. Your Program.cs will probably look something like this:
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers();
// add services that were previously added in ConfigureServices()
var app = builder.Build();
var userManager = app.Services.GetRequiredService<UserManager<MyIdentityUser>>();
var roleManager = app.Services.GetRequiredService<RoleManager<MyIdentityRole>>();
MyIdentityDataInitializer.SeedData(userManager, roleManager);
app.UseAuthentication();
app.UseStaticFiles();
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
*Edit: To fix your error, (and as the link #tappetyclick directed you to explains), you'll need to first create a scope in order to get references to your UserManager and RoleManager objects:
using (var scope = app.Services.CreateScope())
{
var userManager = scope.ServiceProvider.GetRequiredService<UserManager<MyIdentityUser>>();
var roleManager = scope.ServiceProvider.GetRequiredService<RoleManager<MyIdentityRole>>();
MyIdentityDataInitializer.SeedData(userManager, roleManager);
}

There is an error in app.UseMigrationsEndPoint(), if this cant be solved can guide me to remove asp.net identity files (which is used to create login)

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.ResponseCompression;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using OfflineEventManagment.Data;
using OfflineEventManagment.Areas;
using System;
using System.Collections.Generic;
using System.IO.Compression;
using System.Linq;
using System.Threading.Tasks;
namespace OfflineEventManagment
{
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 void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<UserContext>(options =>
options.UseSqlServer(
Configuration.GetConnectionString("DefaultConnection")));
services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = false)
.AddEntityFrameworkStores<UserContext>();
services.AddControllersWithViews();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.Use(async (ctx, next) =>
{
await next();
if (ctx.Response.StatusCode == 404 && !ctx.Response.HasStarted)
{
//Re-execute the request so the user gets the error page
string originalPath = ctx.Request.Path.Value;
ctx.Items["originalPath"] = originalPath;
ctx.Request.Path = "/Error/_404";
await next();
}
});
if (env.IsDevelopment())
{
//Error
app.UseMigrationsEndPoint();
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Home/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
endpoints.MapRazorPages();
});
}
}
}
Here is The Image
**Can anyone help me solve this? I can't figure why there is such an error, if this error cant be solved, can asp.net core identity code can be removed? if so, how?
entitycore identity cannot create context file, also I cann't see database file for this particular project only!
**Or Should I create New Project?

I recreated a project and encountered the same error as you, as follows:
Then I introduced the package to solve the problem: （Pay attention to the .net version you are using）
Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore
Resutl:
For more information, please refer to this article: https://learn.microsoft.com/en-us/aspnet/core/migration/31-to-50?view=aspnetcore-5.0&tabs=visual-studio#usedatabaseerrorpage-obsolete

app.UseMigrationsEndPoint();
It's under the Library below. try this.
Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore

AddCors is not working in asp.net 5.0. How do I enable it?

So my problem is that I tried to enable the CORS, followed the tutorial and it is still not working. My startup.cs looks like this (I include methods to which I tried enabling CORS). Any help would be appreciated:
ConfigureServices method:
public void ConfigureServices(IServiceCollection services)
{
services.AddCors(options=>options.AddDefaultPolicy(builder=>builder.AllowAnyOrigin()));
services.AddControllers();
services.Add(new ServiceDescriptor(typeof(ApplicationDbContext),
new ApplicationDbContext(Configuration.GetConnectionString("DefaultConnection"))));
}
And then I try to use cors in the Configure method.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseHttpsRedirection();
app.UseRouting();
app.UseCors();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
I use the newest .NET core version.
Error specifically is:
Access to XMLHttpRequest at 'http://localhost:5000/api/cities' from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource
Thanks in advance.

Try to use this syntax and assign name to the policy
services.AddCors(o => o.AddPolicy("AllowAnyOrigins", builder =>
{
builder.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader();
}));
.......
app.UseRouting();
app.UseCors("AllowAnyOrigins");
app.UseAuthorization();

Configure Strict Cors .Net Core 3.1

I have a public analytics web api (.Net Core 3.1) that captures basic analytics from my various web apps and sites (page views, etc). I'd very much like to configure cors in a more strict manner as I am well aware of the origins from where traffic should come. It's worth noting that I'm updating this application from .Net Core 2.2 to .Net Core 3.1.
I have the following method in my Startup.cs file
public void ConfigureServices(IServiceCollection services)
{
...
ConfigureCors(services);
}
private void ConfigureCors(IServiceCollection services)
{
// https://weblog.west-wind.com/posts/2016/Sep/26/ASPNET-Core-and-CORS-Gotchas
services.AddCors(options =>
{
options.AddPolicy("CorsPolicy",
builder => builder.WithOrigins(AppConfiguration.CorsOrigins)
.AllowAnyMethod()
.AllowAnyHeader());
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseCors("CorsPolicy");
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers().RequireAuthorization();
});
}
AppConfiguration is a class I use to handle configurations and it grabs json values using the following:
public string[] CorsOrigins => _config["CorsOrigins"].Split(',');
In appsettings.Development.json, I have "CorsOrigins": "*"
I'd very much like to specify strict origins in the appsettings.Production.json and appsettings.Staging.json files.
E.g.
"CorsOrigins": "https://subdomain.example.com,https://www.example.com,https://example.com", but on deployment, I get a status of 502 whenever by websites/apps hit the various endpoints.
"CorsOrigins": "*" works on local so there can't be anything wrong with the Startup.cs file as far as I'm aware.
Update: "CorsOrigins": "*" actually does not work for the staging or production environments either. Now I'm even more confused. To be clear, this is a cors question. The following worked fine before upgrading to .Net Core 3.1:
private void ConfigureCors(IServiceCollection services)
services.AddCors(options =>
{
options.AddPolicy("CorsPolicy",
builder => builder.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader()
.AllowCredentials());
});
}

Take care to place the UseCors at the right location. From the docs:
The call to UseCors must be placed after UseRouting, but before
UseAuthorization.
As noted in the comments, allowing "*" as origin isn't allowed with AllowCredentials.
Here's a working example of a CORS configuration from my ASPNET Core 3.1 project. It does the config in the Configure method instead of ConfigureServices, but same content:
// Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddCors();
// etc
}
public void Configure(IApplicationBuilder app)
{
// other configs
app.UseRouting();
// CORS configuration. Expects allowed origins as comma-separated list in config under 'Cors:AllowedOrigins'.
string configuredOrigins = Configuration["Cors:AllowedOrigins"] ?? throw new ArgumentNullException("Cors:AllowedOrigins");
string[] origins = configuredOrigins.Split(',', ';').Select(i => i.Trim()).ToArray();
app.UseCors(policy => policy
.WithOrigins(origins)
.AllowAnyMethod()
.AllowAnyHeader()
.AllowCredentials() // Required by SignalR
.WithExposedHeaders(CONTINUATION_HEADER_KEY) // Allow use of custom header
.SetPreflightMaxAge(TimeSpan.FromSeconds(86400))); // Allow caching for 24 hours (depends on browser)
app.UseAuthentication();
app.UseAuthorization();
// other configs
}

Sorry this is a difficult question so there could be a number of reasons it doesnt work but Ive run into a similar issue and resolved its by altering the cors invocation in the Configure() function. The Configure() function is a gets called during runtime and acts as an http request pipeline so in some cases order of execution matters (https://learn.microsoft.com/en-us/aspnet/core/fundamentals/startup?view=aspnetcore-3.1#the-configure-method)
You could try the following:
Change the current:
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseCors("CorsPolicy"); //Move this line
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers().RequireAuthorization();
});
}
To:
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseCors("CorsPolicy"); // Here
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers().RequireAuthorization();
});
}
Hence the first operation in the http pipeline would be to validate cors.
I rate this is a fair bet as from your question it sounds like you dont get an app initialise error but rather a runtime client request time error.
I dont know for certain if this will solve the problem but maybe it helps!

System.InvalidOperationException when using HttpContext.Session with use.Session(); set

I am developing a .NET Core 3.0 application using Razor pages for a project in my studies. The application is going to use a login feature and I am want to use sessions to send data and verify what user is logged in.
For this I have decided to use HttpContext.Session to get and set strings during post.
When I use the line: HttpContext.Session.SetString("username", "test");
I get the error: System.InvalidOperationException: 'Session has not been configured for this application or request.'
After some extensive googling and using a Microsoft doc I cannot seem to find a solution. Everywhere I get the answer that I need to include services.AddSession and app.UseSession(); in my Startup.cs file which I do, These are all added before the 'UseMvc();' lines.
I have run out of options and my software teacher does not want to give me any help aside from "are you using the correct version" which I think I do according to the Microsoft docs.
What am I missing that causes this error? How can I get sessions to work? Am I implementing it wrong?
Below is my Startup.cs class:
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 void ConfigureServices(IServiceCollection services)
{
services.AddDistributedMemoryCache();
services.AddRazorPages();
services.AddSession(options =>
{
options.Cookie.HttpOnly = true;
options.Cookie.IsEssential = true;
options.IdleTimeout = TimeSpan.FromSeconds(10);
});
services.AddMvc(option => option.EnableEndpointRouting = false);
}
// 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();
}
else
{
app.UseExceptionHandler("/Error");
}
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
});
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseSession();
app.UseMvc();
}
}
Notable is when I use app.UseHttpContextItemsMiddleware(); between
app.UseSession(); and app.UseMvc(); I get an Intellisense error that says IApplicationBuilder does not have this method. In the Microsoft docs it is show that this string is included in Startup.cs.

Everywhere I get the answer that I need to include services.AddSession and app.UseSession(); in my Startup.cs file which I do, These are all added before the 'UseMvc();' lines.
Yes, you're right. However, either invoke UseMvc() or invoke UseRouting()+ UseEndpoints(), but don't invoke them both. As of ASP.NET 3.0, I would suggest you should use UseRouting()+ UseEndpoints() instead of the UseMvc().
In your original codes, the UseEndpoints() is triggered before UseSession() which makes the MVC/Razor Page execute before UseSession(). To fix that issue, change your code as below:
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Error");
}
app.UseHttpsRedirection();
app.UseStaticFiles();
// put UseSession before the line where you want to get the session.
// at least, you should put it before `app.UseEndpoints(...)`
app.UseSession();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
// if you need mvc, don't forget to
// add `services.AddControllersWithViews`
// and add this line
endpoints.MapControllerRoute(
name: "default-controller",
pattern: "{controller=Home}/{action=Index}/{id?}");
});
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseSession();
app.UseMvc();
}