Introducing IHostedService

Hosted services have been a thing since ASP.NET Core 2.0 and can be used to run tasks asynchronously in the background of your application. They can be used to fetch data periodically, do some calculations in the background, or do some cleanup. You can also use them to send preconfigured emails – or whatever you need to do in the background.

Hosted services are basically simple classes that implement the IHostedService interface. You call them with the following code:

public class SampleHostedService : IHostedService
{
    public Task StartAsync(CancellationToken 
      cancellationToken)
    {
    }
    public Task StopAsync(CancellationToken 
     cancellationToken)
    {
    }
}

IHostedService needs to implement a StartAsync() method and a StopAsync() method. The StartAsync...