使用依赖注入调度 Quartz.net 作业

Question

I'm working on my first project with EF Core, and Dependency Injecion for the DB Context. However I'm running into an issue because Quartz.net 3 seems to not allow any parameters on the ImportJob Class. So my method of DI, doesn't work in this instance. I know I want a new context, because this is going to run in the background, is there a different way to create a DB Context so that I can Execute this task?

public class ImportJob : IJob
{
    private readonly SContext _db;

    //Quartz.net doesn't appear to like that I'm injecting these, 
    //because if I remove this parameter, execute...executes.
    public ImportJob(SContext db)
    {
        _db = db;
    }

    public Task Execute(IJobExecutionContext context)
    {
        var cc = new CC(_db);
        return Task.CompletedTask;
    }
}

Answer 1

One way is to use the StdSchedulerFactory , a Job Factory that implements IJobFactory and takes a IServiceProvider

Example

public class JobFactory : IJobFactory
{
   private readonly IServiceProvider _serviceProvider;

   public JobFactory(IServiceProvider serviceProvider)
      => _serviceProvider = serviceProvider;

   public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
   {
      try
      {
         var jobDetail = bundle.JobDetail;
         var jobType = jobDetail.JobType;
         return _serviceProvider.GetService(jobType) as IJob;
      }
      catch (Exception ex)
      {

         throw new SchedulerException($"Problem instantiating class '{bundle.JobDetail.JobType.FullName}'", ex);
      }
   }

   public void ReturnJob(IJob job)
      => (job as IDisposable)?.Dispose();
}

Depending on your DI framework the registrations would look a little like this

// register, your container as an IServiceProvider
container.RegisterInstance<IServiceProvider>(container);

// create the scheduler
var scheduler = await StdSchedulerFactory.GetDefaultScheduler(cancellationTokenSource.Token);

// add your factory to the scheduler
scheduler.JobFactory = new JobFactory(container);

// register the scheduler
container.RegisterInstance(scheduler);

// register your jobs

container.Collection.Register<IJob>(GetType().Assembly);

Then you jobs can look like this

public class ImportJob : IJob
{
    private readonly SContext _db;

    //Quartz.net doesn't appear to like that I'm injecting these, 
    //because if I remove this parameter, execute...executes.
    public ImportJob(SContext db)
    {
        _db = db;
    }

    public Task Execute(IJobExecutionContext context)
    {
        var cc = new CC(_db);
        return Task.CompletedTask;
    }
}

_{Note : This is the basic idea not a complete example, and it will depend a lot on your own setup and framework}

In short, what the above does is when Quartz creates a job it uses your Factory and container to spin up the job allowing for injection.