后台任务
摘自：Background tasks with hosted services in ASP.NET Core
BackgroundService is a base class for implementing a long running IHostedService.
ExecuteAsync(CancellationToken) is called to run the background service. The implementation returns a Task that represents the entire lifetime of the background service. No further services are started until ExecuteAsync becomes asynchronous, such as by calling . Avoid performing long, blocking initialization work in . The host blocks in StopAsync(CancellationToken) waiting for to complete.awaitExecuteAsyncExecuteAsync
The cancellation token is triggered when IHostedService.StopAsync is called. Your implementation of should finish promptly when the cancellation token is fired in order to gracefully shut down the service. Otherwise, the service ungracefully shuts down at the shutdown timeout. For more information, see the IHostedService interface section.ExecuteAsync
总结
当继承 IHostedService 接口实现 BackgroundService 或者 BackgroundTasks ，其实现类在注入时，不受注入的先后顺序影响。
下面的例子，ConsumerManager 依赖 IKafkaEventBusContainer 的实现：
1 | serviceCollection.AddHostedService<ConsumerManager>(); |
参考：