DbContextFactory injection instead of DbContext in the Blazor Server

[xenbill]

When I am injecting dbContext (page740) and I am trying to add or update Customers
I am getting an exception

Microsoft.EntityFrameworkCore.Query: Error: An exception occurred while iterating over the results of a query for context type 'Xenbill.Shared.NorthwindContext'. 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.SingleQueryingEnumerable1.AsyncEnumerator.MoveNextAsync()

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.SingleQueryingEnumerable1.AsyncEnumerator.MoveNextAsync() Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer: Warning: Unhandled exception rendering component: 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.

After a little research I injected dbContextFactory instead of DbContext directly.
So I create new instances of dbContext every time I use NorthwindService ( which is Transient) .
I don't have exceptions when I am implementing this way.

Is this ok ?

btw Thx for this great book !!

[markjprice]

I will try to investigate this issue next weekend. My initial thought is that, yes, your fix is the proper way to go.