作为一枚后端程序狗，项目实践常遇到定时任务的工作，最容易想到的的思路就是利用Windows计划任务/wndows service程序/Crontab程序等主机方法在主机上部署定时任务程序/脚本。
但是很多时候，若使用的是共享主机或者受控主机，这些主机不允许你私自安装exe程序、Windows服务程序。
码甲会想到在web程序中做定时任务， 目前有两个方向：
①.AspNetCore自带的HostService， 这是一个轻量级的后台服务， 需要搭配timer完成定时任务
②.老牌Quartz.Net组件，支持复杂灵活的Scheduling、支持ADO/RAM Job任务存储、支持集群、支持监听、支持插件。
此处我们的项目使用稍复杂的Quartz.net实现web定时任务。
项目背景
最近需要做一个计数程序：采用redis计数，设定每小时将当日累积数据持久化到关系型数据库sqlite。
添加Quartz.Net Nuget 依赖包：<PackageReference Include="Quartz" Version="3.0.6" />
①.定义定时任务内容： Job
②.设置触发条件： Trigger
③.将Quartz.Net集成进AspNet Core
头脑风暴
IScheduler类包装了上述背景需要完成的第①②点工作 ，SimpleJobFactory定义了生成指定的Job任务的过程，这个行为是利用反射机制调用无参构造函数构造出的Job实例。下面是源码：
//----------------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>
