//----------------选自Quartz.Simpl.SimpleJobFactory类-------------
using System;
using Quartz.Logging;
using Quartz.Spi;
using Quartz.Util;
namespace Quartz.Simpl
{
    /// <summary>
    /// The default JobFactory used by Quartz - simply calls
    /// <see cref="ObjectUtils.InstantiateType{T}" /> on the job class.
    /// </summary>
    /// <seealso cref="IJobFactory" />
    /// <seealso cref="PropertySettingJobFactory" />
    /// <author>James House</author>
    /// <author>Marko Lahma (.NET)</author>
    public class SimpleJobFactory : IJobFactory
    {
        private static readonly ILog log = LogProvider.GetLogger(typeof (SimpleJobFactory));

        /// <summary>
        /// Called by the scheduler at the time of the trigger firing, in order to
        /// produce a <see cref="IJob" /> instance on which to call Execute.
        /// </summary>
        /// <remarks>
        /// It should be extremely rare for this method to throw an exception -
        /// basically only the case where there is no way at all to instantiate
        /// and prepare the Job for execution.  When the exception is thrown, the
        /// Scheduler will move all triggers associated with the Job into the
        /// <see cref="TriggerState.Error" /> state, which will require human
        /// intervention (e.g. an application restart after fixing whatever
        /// configuration problem led to the issue with instantiating the Job).
        /// </remarks>
        /// <param name="bundle">The TriggerFiredBundle from which the <see cref="IJobDetail" />
        ///   and other info relating to the trigger firing can be obtained.</param>
        /// <param name="scheduler"></param>
        /// <returns>the newly instantiated Job</returns>
        /// <throws>  SchedulerException if there is a problem instantiating the Job. </throws>
        public virtual IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
        {
            IJobDetail jobDetail = bundle.JobDetail;
            Type jobType = jobDetail.JobType;
            try
            {
                if (log.IsDebugEnabled())
                {
                    log.Debug($"Producing instance of Job '{jobDetail.Key}', class={jobType.FullName}");
                }

                return ObjectUtils.InstantiateType<IJob>(jobType);
            }
            catch (Exception e)
            {
                SchedulerException se = new SchedulerException($"Problem instantiating class '{jobDetail.JobType.FullName}'", e);
                throw se;
            }
        }

        /// <summary>
        /// Allows the job factory to destroy/cleanup the job if needed.
        /// No-op when using SimpleJobFactory.
        /// </summary>
        public virtual void ReturnJob(IJob job)
        {
            var disposable = job as IDisposable;
            disposable?.Dispose();
        }
    }
}

//------------------节选自Quartz.Util.ObjectUtils类-------------------------
 public static T InstantiateType<T>(Type type)
{
     if (type == null)
     {
          throw new ArgumentNullException(nameof(type), "Cannot instantiate null");
     }
     ConstructorInfo ci = type.GetConstructor(Type.EmptyTypes);
     if (ci == null)
     {
          throw new ArgumentException("Cannot instantiate type which has no empty constructor", type.Name);
     }
     ]);
}

很多时候，定义的Job任务依赖了其他组件（Job实例化时多参），此时默认的SimpleJobFactory不能满足实例化要求， 需要考虑将Job任务作为依赖注入组件，加入依赖注入容器。

// -------每小时将redis数据持久化到sqlite， 每日凌晨跳针，持久化昨天全天数据---------------------
public class UsageCounterSyncJob : IJob
{
        private readonly EqidDbContext _context;
        private readonly IDatabase _redisDB1;
        private readonly ILogger _logger;
        public UsageCounterSyncJob(EqidDbContext context, RedisDatabase redisCache, ILoggerFactory loggerFactory)
        {
            _context = context;
            _redisDB1 = redisCache[];
            _logger = loggerFactory.CreateLogger<UsageCounterSyncJob>();
        }
         public async Task Execute(IJobExecutionContext context)
        {
            // 触发时间在凌晨，则同步昨天的计数
            var _day = DateTime.Now.ToString("yyyyMMdd");
            )
                _day = DateTime.Now.AddDays(-).ToString("yyyyMMdd");

            await SyncRedisCounter(_day);
            _logger.LogInformation("[UsageCounterSyncJob] Schedule job executed.");
        }
        ......
 }

namespace EqidManager
{
    using IOCContainer = IServiceProvider;
    // Quartz.Net启动后注册job和trigger
    public class QuartzStartup
    {
        public IScheduler _scheduler { get; set; }

        private readonly ILogger _logger;
        private readonly IJobFactory iocJobfactory;
        public QuartzStartup(IOCContainer IocContainer, ILoggerFactory loggerFactory)
        {
            _logger = loggerFactory.CreateLogger<QuartzStartup>();
            iocJobfactory = new IOCJobFactory(IocContainer);
            var schedulerFactory = new StdSchedulerFactory();
            _scheduler = schedulerFactory.GetScheduler().Result;
            _scheduler.JobFactory = iocJobfactory;
        }

        public void Start()
        {
            _logger.LogInformation("Schedule job load as application start.");
            _scheduler.Start().Wait();

            var UsageCounterSyncJob = JobBuilder.Create<UsageCounterSyncJob>()
               .WithIdentity("UsageCounterSyncJob")
               .Build();

            var UsageCounterSyncJobTrigger = TriggerBuilder.Create()
                .WithIdentity("UsageCounterSyncCron")
                .StartNow()
                // 每隔一小时同步一次
                .WithCronSchedule("0 0 * * * ?")      // Seconds,Minutes,Hours，Day-of-Month，Month，Day-of-Week，Year（optional field）
                .Build();
            _scheduler.ScheduleJob(UsageCounterSyncJob, UsageCounterSyncJobTrigger).Wait();

            _scheduler.TriggerJob(new JobKey("UsageCounterSyncJob"));
        }

        public void Stop()
        {
            if (_scheduler == null)
            {
                return;
            }

            ))
                _scheduler = null;
            else
            {
            }
            _logger.LogCritical("Schedule job upload as application stopped");
        }
    }

    /// <summary>
    /// IOCJobFactory ：实现在Timer触发的时候注入生成对应的Job组件
    /// </summary>
    public class IOCJobFactory : IJobFactory
    {
        protected readonly IOCContainer Container;

        public IOCJobFactory(IOCContainer container)
        {
            Container = container;
        }

        //Called by the scheduler at the time of the trigger firing, in order to produce
        //     a Quartz.IJob instance on which to call Execute.
        public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
        {
            return Container.GetService(bundle.JobDetail.JobType) as IJob;
        }

        // Allows the job factory to destroy/cleanup the job if needed.
        public void ReturnJob(IJob job)
        {
        }
    }
}

//-------------------------------截取自Startup文件------------------------
......
services.AddTransient<UsageCounterSyncJob>();      // 这里使用瞬时依赖注入
services.AddSingleton<QuartzStartup>();
......

// 绑定Quartz.Net
public void Configure(IApplicationBuilder app, Microsoft.AspNetCore.Hosting.IApplicationLifetime lifetime, ILoggerFactory loggerFactory)
{
     var quartz = app.ApplicationServices.GetRequiredService<QuartzStartup>();
     lifetime.ApplicationStarted.Register(quartz.Start);
     lifetime.ApplicationStopped.Register(quartz.Stop);
}

更多资料请参考:  https://blogs.technet.microsoft.com/erezs_iis_blog/2013/06/26/new-feature-in-iis-8-5-idle-worker-process-page-out/