问题
I get the following error when visiting my SPA site which makes some calls to the API when loaded:
A second operation started on this context before a previous asynchronous operation completed. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context. Any instance members are not guaranteed to be thread safe.
If I don't use the same context and try to update values I get the following error, see this question:
Entity Framework 6 - Dependency Injection with Unity - Repository pattern - Add or Update exception for many to many relationship
The relationship between the two objects cannot be defined because they are attached to different ObjectContext objects.
This means that I can't use the answer suggested here to use multiple contexts:
https://stackoverflow.com/a/20635076/3850405
UnityConfig.cs:
container.RegisterType<DbContext>(new HierarchicalLifetimeManager());
container.RegisterType<ISupplierRepository, SupplierRepository>();
container.RegisterType<IContactRepository, ContactRepository>();
How can I solve this?
回答1:
Solved it with PerRequestLifetimeManager from Microsoft.Practices.Unity.Mvc.
container.RegisterType<DbContext>(new PerRequestLifetimeManager());
container.RegisterType<ISupplierRepository, SupplierRepository>();
container.RegisterType<IContactRepository, ContactRepository>();
来源：https://stackoverflow.com/questions/45146126/c-sharp-ef6-make-multiple-async-calls-to-one-context-using-unity-asp-net-web-a