监听器是在
scheduler
事件发生时能够执行动作的对象。可以看出，
TriggerListeners
接收与
triggers
相关的事件，而
JobListeners
则接收与
Job
相关的事件。
Trigger
相关的事件包括：
trigger
触发、
trigger
未触发，以及
trigger
完成（由
trigger
触发的任务被完成）。
///
<summary>
/// The interface to be implemented by classes that want to be informed when a
/// <see cref="Trigger" /> fires. In general, applications that use a
/// <see cref="IScheduler" /> will not have use for this mechanism.
/// </summary>
/// <seealso cref="IScheduler" />
/// <seealso cref="Trigger" />
/// <seealso cref="IJobListener" />
/// <seealso cref="JobExecutionContext" />
/// <author>James House</author>
public interface ITriggerListener
{
/// <summary>
/// Get the name of the <see cref="ITriggerListener" />.
/// </summary>
string Name { get; }
/// <summary>
/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />
/// has fired, and it's associated <see cref="JobDetail" />
/// is about to be executed.
/// <p>
/// It is called before the <see cref="VetoJobExecution" /> method of this
/// interface.
/// </p>
/// </summary>
/// <param name="trigger">The <see cref="Trigger" /> that has fired.</param>
/// <param name="context">
/// The <see cref="JobExecutionContext" /> that will be passed to the <see cref="IJob" />'s<see cref="IJob.Execute" /> method.
/// </param>
void TriggerFired(Trigger trigger, JobExecutionContext context);
/// <summary>
/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />
/// has fired, and it's associated <see cref="JobDetail" />
/// is about to be executed.
/// <p>
/// It is called after the <see cref="TriggerFired" /> method of this
/// interface.
/// </p>
/// </summary>
/// <param name="trigger">The <see cref="Trigger" /> that has fired.</param>
/// <param name="context">
/// The <see cref="JobExecutionContext" /> that will be passed to
/// the <see cref="IJob" />'s<see cref="IJob.Execute" /> method.
/// </param>
bool VetoJobExecution(Trigger trigger, JobExecutionContext context);
/// <summary>
/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />
/// has misfired.
/// <p>
/// Consideration should be given to how much time is spent in this method,
/// as it will affect all triggers that are misfiring. If you have lots
/// of triggers misfiring at once, it could be an issue it this method
/// does a lot.
/// </p>
/// </summary>
/// <param name="trigger">The <see cref="Trigger" /> that has misfired.</param>
void TriggerMisfired(Trigger trigger);
/// <summary>
/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />
/// has fired, it's associated <see cref="JobDetail" />
/// has been executed, and it's <see cref="Trigger.Triggered" /> method has been
/// called.
/// </summary>
/// <param name="trigger">The <see cref="Trigger" /> that was fired.</param>
/// <param name="context">
/// The <see cref="JobExecutionContext" /> that was passed to the
/// <see cref="IJob" />'s<see cref="IJob.Execute" /> method.
/// </param>
/// <param name="triggerInstructionCode">
/// The result of the call on the <see cref="Trigger" />'s<see cref="Trigger.Triggered" /> method.
/// </param>
void TriggerComplete(Trigger trigger, JobExecutionContext context, SchedulerInstruction triggerInstructionCode);
}
与任务相关的事件包括：即将被执行的任务的通知和任务已经执行完毕的通知。
The.JobListener Interface
///
<summary>
/// The interface to be implemented by classes that want to be informed when a
/// <see cref="JobDetail" /> executes. In general, applications that use a
/// <see cref="IScheduler" /> will not have use for this mechanism.
/// </summary>
/// <seealso cref="IScheduler" />
/// <seealso cref="IJob" />
/// <seealso cref="JobExecutionContext" />
/// <seealso cref="JobExecutionException" />
/// <seealso cref="ITriggerListener" />
/// <author>James House</author>
public interface IJobListener
{
/// <summary>
/// Get the name of the <see cref="IJobListener" />.
/// </summary>
string Name { get; }
/// <summary>
/// Called by the <see cref="IScheduler" /> when a <see cref="JobDetail" />
/// is about to be executed (an associated <see cref="Trigger" />
/// has occured).
/// <p>
/// This method will not be invoked if the execution of the Job was vetoed
/// by a <see cref="ITriggerListener" />.
/// </p>
/// </summary>
/// <seealso cref="JobExecutionVetoed(JobExecutionContext)" />
void JobToBeExecuted(JobExecutionContext context);
/// <summary>
/// Called by the <see cref="IScheduler" /> when a <see cref="JobDetail" />
/// was about to be executed (an associated <see cref="Trigger" />
/// has occured), but a <see cref="ITriggerListener" /> vetoed it's
/// execution.
/// </summary>
/// <seealso cref="JobToBeExecuted(JobExecutionContext)" />
void JobExecutionVetoed(JobExecutionContext context);
/// <summary>
/// Called by the <see cref="IScheduler" /> after a <see cref="JobDetail" />
/// has been executed, and be for the associated <see cref="Trigger" />'s
/// <see cref="Trigger.Triggered" /> method has been called.
/// </summary>
void JobWasExecuted(JobExecutionContext context, JobExecutionException jobException);
}
使用你自定义的监听器
创建监听器很简单，创建一个实现Quartz.ITriggerListener或（和）Quartz.IJobListener的接口。监听器然后在执行的时候注册到scheduler中，而且必须给定一个名字（或者，它们必须通过他们的Name属性来介绍自己）。监听器可以被注册为
“
全局
”
的或者
“
非全局
”
。
“
全局
”
监听器接收所有triggers/jobs产生的事件，而
“
非全局
”
监听器只接受那些通过TriggerListenerNames属性 或 JobListenerNames()方法显式指定监听器名的triggers/jobs所产生的事件。
正如上面所说的那样，监听器在运行时向
scheduler
注册，并且不被存储在
jobs
和
triggers
的
JobStore
中。
Jobs
和
Trigger
只存储了与他们相关的监听器的名字。因此，每次应用运行的时候，都需要向
scheduler
重新注册监听器。
向 Scheduler中加入一个JobListener
scheduler.
AddGlobalJobListener
(myJobListener);
或者
scheduler.AddJobListener(myJobListener);
Quartz
的大多数用户不使用监听器，但是当应用需要创建事件通知而
Job
本身不能显式通知应用，则使用监听器非常方便。
本文转自 张善友 51CTO博客，原文链接：http://blog.51cto.com/shanyou/73992，如需转载请自行联系原作者
