1 第一个用户访问我们的WebApplication的时候，Application_Start才运行。
 2 
 3 //0 15 10 ? * *" ：Fire at 10:15am every day 
 4             CronTrigger trigger = new CronTrigger("trigger1", "group1", "job1", "group1");
 5             trigger.CronExpressionString = “0 15 10 ? * *”;
 6 
 7 
 8 //每隔一段时间执行任务
 9 IScheduler sched;
10  ISchedulerFactory sf = new StdSchedulerFactory();
11             sched = sf.GetScheduler();
12             JobDetail job = new JobDetail("job1", "group1", typeof(IndexJob));//IndexJob为实现了IJob接口的类
13             DateTime ts = TriggerUtils.GetNextGivenSecondDate(null, 5);//5秒后开始第一次运行
14             TimeSpan interval =  TimeSpan.FromHours(1);//每隔1小时执行一次
15  Trigger trigger = new SimpleTrigger("trigger1", "group1", "job1", "group1", ts, null,
16                                          SimpleTrigger.RepeatIndefinitely, interval);//每若干小时运行一次，小时间隔由appsettings中的IndexIntervalHour参数指定
17 
18             sched.AddJob(job, true);
19             sched.ScheduleJob(trigger);
20             sched.Start();
21 要关闭任务定时则需要sched.Shutdown(true)