Question

I tried Quartz.com documentation & googled for couple for hours…but could not find single good article on how to get Next Job (which is supposr to fire in future).

I am using CronTrigger Expression to Schedule jobs, using VB.net (winforms). jobs works fine…however I would like my users to see when will it FIRE next. I am storing CronExpression in my database, Can I use that Expression to show next Fire Date/Time to my end users? or if there is any other way possible please advise (with a simple samply).

Thanks

Edit

Following Code Returns next job will fire after 12 minutes instead of 20 minute

    Dim exp As CronExpression = New CronExpression("0 0/20 * * * ?")
    Dim nextFire As String = exp.GetNextValidTimeAfter(DateTime.Now)
    MsgBox(nextFire)

Answer 1

You can create a new JobKey

JobKey jobKey = new JobKey(jobName, groupName);

and use the key to fetch the job detail:

var detail = scheduler.GetJobDetail(jobKey);

this is a simple function which does what you’re looking for:

    private DateTime getNextFireTimeForJob(IScheduler scheduler, string jobName, string groupName = "")
    {
        JobKey jobKey = new JobKey(jobName, groupName);
        DateTime nextFireTime = DateTime.MinValue;

        bool isJobExisting = Scheduler.CheckExists(jobKey);
        if (isJobExisting)
        {
            var detail = scheduler.GetJobDetail(jobKey);
            var triggers = scheduler.GetTriggersOfJob(jobKey);

            if (triggers.Count > 0)
            {
                var nextFireTimeUtc = triggers[0].GetNextFireTimeUtc();
                nextFireTime = TimeZone.CurrentTimeZone.ToLocalTime(nextFireTimeUtc.Value.DateTime);
            }
        }

        return (nextFireTime);
    }

It works only if you have one trigger per job.
If there’s more than one trigger in your job you can loop through them:

foreach (ITrigger trigger in triggers)
{
    Console.WriteLine(jobKey.Name);
    Console.WriteLine(detail.Description);
    Console.WriteLine(trigger.Key.Name);
    Console.WriteLine(trigger.Key.Group);
    Console.WriteLine(trigger.GetType().Name);
    Console.WriteLine(scheduler.GetTriggerState(trigger.Key));
    DateTimeOffset? nextFireTime = trigger.GetNextFireTimeUtc();
    if (nextFireTime.HasValue)
    {
        Console.WriteLine(TimeZone.CurrentTimeZone.ToLocalTime(nextFireTime.Value.DateTime).ToString());
    }
}

or using Linq (System.Linq) :

 var myTrigger = triggers.Where(f => f.Key.Name == "[trigger name]").SingleOrDefault();