Blazor Server - Circuit Error when using asynchronous UserManager methods

Question

im currently working on a blazor server web app where is use identitycore to manage the users. I got a razor component where the user have to input the data for the user account. this page should use a service that get injected through dependency injection. but when i try to create the user, i got following exceptions:

[13:56:45 ERR] An exception occurred while iterating over the results of a query for context type 'ProjectName.Data.Context.DataContext'.
System.InvalidOperationException: A second operation was started on this context instance before a previous operation completed. This is usually caused by different threads concurrently using the same instance of DbContext. For more information on how to avoid threading issues with DbContext, see https://go.microsoft.com/fwlink/?linkid=2097913.
   at Microsoft.EntityFrameworkCore.Infrastructure.Internal.ConcurrencyDetector.EnterCriticalSection()
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
System.InvalidOperationException: A second operation was started on this context instance before a previous operation completed. This is usually caused by different threads concurrently using the same instance of DbContext. For more information on how to avoid threading issues with DbContext, see https://go.microsoft.com/fwlink/?linkid=2097913.
   at Microsoft.EntityFrameworkCore.Infrastructure.Internal.ConcurrencyDetector.EnterCriticalSection()
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()

[13:56:45 WRN] Unhandled exception rendering component: Cannot access a disposed object.
System.ObjectDisposedException: Cannot access a disposed object.
   at Microsoft.AspNetCore.Components.RenderTree.ArrayBuilder`1.GrowBuffer(Int32 desiredCapacity)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()

[13:56:45 WRN] Unhandled exception rendering component: Cannot access a disposed object.
Object name: 'UserManager`1'.
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'UserManager`1'.
   at Microsoft.AspNetCore.Identity.UserManager`1.ThrowIfDisposed()
   at Microsoft.AspNetCore.Identity.UserManager`1.get_SupportsUserLockout()
   at Microsoft.AspNetCore.Identity.UserManager`1.CreateAsync(TUser user)
   at ProjectName.Service.Services.UserService.CreateUser(AppUser user) in C:\Users\erikm\source\repos\ProjectName\ProjectName.Service\Services\UserService.cs:line 66
   at ProjectName.Web.Pages.Employee.CompanyEmployees.CreateHandler(GridCommandEventArgs arg) in C:\Users\erikm\source\repos\ProjectName\ProjectName.Web\Pages\Employee\CompanyEmployees.razor:line 67
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Telerik.Blazor.Components.Common.TableGridBase`2.InvokeEventAsync(EventCallback`1 event, TableCommandEventArgs args)
   at Telerik.Blazor.Components.Common.TableGridBase`2.InvokeCreateEventAsync(TableCommandEventArgs args)
   at Telerik.Blazor.Components.Common.TableGridBase`2.InvokeSaveEventAsync(TableCommandEventArgs args)
   at Telerik.Blazor.Components.Common.TableGridBase`2.ExecuteSaveCommandAsync(TableCommandEventArgs args)
   at Telerik.Blazor.Components.Common.TableGridBase`2.ExecuteValidatedCommand(TableCommandEventArgs args)
   at Telerik.Blazor.Components.TelerikGrid`1.ExecuteValidatedCommand(TableCommandEventArgs args)
   at Telerik.Blazor.Components.Common.TableGridBase`2.ExecuteCommand(Object commandArgs)
   at Telerik.Blazor.Components.Common.Grid.GridEditForm`1.FireCommand(String name)
   at Telerik.Blazor.Components.Common.Grid.GridEditForm`1.Update()
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Telerik.Blazor.Components.TelerikForm.OnSubmitHandler()
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)

my code looks like that: Razor Page

    [Inject]
    private IUserService _userService { get; set; }

    private async Task CreateHandler(GridCommandEventArgs arg)
    {
        if (arg.Item is AppUser user)
        {
            user.CompanyId = Company.Id;
            user.UserName = user.Email;
            await _userService.CreateUser(user);
        }
    }

and the service layer:

    private readonly UserManager<AppUser> _userManager;
    private readonly IDbContextFactory<DataContext> _dataContextFactory;
    public UserService(UserManager<AppUser> userManager, IDbContextFactory<DataContext> dataContextFactory)
    {
        _userManager = userManager;
        _dataContextFactory = dataContextFactory;
    }

    public async Task<AppUser?> CreateUser(AppUser user)
    {
        IdentityResult result = await _userManager.CreateAsync(user);
        return result.Succeeded ? user : null;
    }

and also my Program.cs

            var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");
            builder.Services.AddDbContextFactory<DataContext>(options =>
            {
                options.UseSqlServer(connectionString, sqlServerOptionsAction: sqlOptions =>
                {
                    sqlOptions.EnableRetryOnFailure();
                });
            });

            builder.Services.AddIdentity<AppUser, AppRole>(options =>
                {
                    options.SignIn.RequireConfirmedAccount = false;
                })
                .AddEntityFrameworkStores<DataContext>()
                .AddDefaultTokenProviders();

            builder.Services.AddTransient<IUserService, UserService>();

im expecting that i can create user asynchronously and in the service layer. Im using.net 7.0 with all relevant packages updated to the latest version (7.0.0 atm)

Answer 1

UserManager is based on EFCore,and you registed the dbcontext as below:

builder.Services.AddDbContextFactory<DataContext>(options =>
            {
                options.UseSqlServer(connectionString, sqlServerOptionsAction: sqlOptions =>
                {
                    sqlOptions.EnableRetryOnFailure();
                });
            });

if you didn't set the lifetime when you regist the context,it would be scoped by default,you could try regist it as transident as below:

services.AddDbContext<SomeContext>(options =>options.UseSqlServer(
                        Configuration.GetConnectionString("SomeContextConnection")),ServiceLifetime.Transient);

For more details,you could check this document