public class ScheduledService: IHostedService
{
private readonly CrontabSchedule _crontabSchedule;
private DateTime _nextRun;
private const string Schedule = "0 0 23 * * *"; // run day at 11 pm
public ScheduledService()
{
_crontabSchedule = CrontabSchedule.Parse(Schedule, new CrontabSchedule.ParseOptions{IncludingSeconds = true});
_nextRun = _crontabSchedule.GetNextOccurrence(DateTime.Now);
}
public Task StartAsync(CancellationToken cancellationToken)
{
Task.Run(async () =>
{
while (!cancellationToken.IsCancellationRequested)
{
await Task.Delay(UntilNextExecution(), cancellationToken); // wait until next time
//execute some task
_nextRun = _crontabSchedule.GetNextOccurrence(DateTime.Now);
}
}, cancellationToken);
return Task.CompletedTask;
}
private int UntilNextExecution() => Math.Max(0, (int)_nextRun.Subtract(DateTime.Now).TotalMilliseconds);
public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
}
Cron Expressions refer
https://github.com/atifaziz/NCrontab
