Background Worker Check For When It's Midnight?
I want to create a background worker for a WinForm that triggers code whenever midnight rolls by.
I have an idea of how to do it, but I'm pretty sure it's not the best way to do it.
while(1==1)
{
//if Date开发者_开发百科time.Now == midnight, execute code
//sleep(1second)
}
Use a System.Timers.Timer
and at application start up just calculate the difference between DateTime.Now
and DateTime.Today.AddDays(0)
. Then set the interval for that amount.
I actually did something just like this recently:
public static class DayChangedNotifier
{
private static Timer timer;
static DayChangedNotifier()
{
timer = new Timer(GetSleepTime());
timer.Elapsed += (o, e) =>
{
OnDayChanged(DateTime.Now.DayOfWeek);
timer.Interval = this.GetSleepTime();
};
timer.Start();
SystemEvents.TimeChanged += new EventHandler(SystemEvents_TimeChanged);
}
private static void SystemEvents_TimeChanged(object sender, EventArgs e)
{
timer.Interval = GetSleepTime();
}
private static double GetSleepTime()
{
var midnightTonight = DateTime.Today.AddDays(1);
var differenceInMilliseconds = (midnightTonight - DateTime.Now).TotalMilliseconds;
return differenceInMilliseconds;
}
private static void OnDayChanged(DayOfWeek day)
{
var handler = DayChanged;
if (handler != null)
{
handler(null, new DayChangedEventArgs(day));
}
}
public static event EventHandler<DayChangedEventArgs> DayChanged;
}
AND:
public class DayChangedEventArgs : EventArgs
{
public DayChangedEventArgs(DayOfWeek day)
{
this.DayOfWeek = day;
}
public DayOfWeek DayOfWeek { get; private set; }
}
Useage: DayChangedNotified.DayChanged += ....
Instead you could user a Timer and set the timer tick interval to be the time between Now() and midnight.
I have no idea why polling solutions were voted up when Microsoft solved this type of problem years ago by adding a windows service to handle timing. Just create a scheduled task to run the exe. No extra overhead.
you can use Quartz to schedule that. Maybe is like a cannon to kill a mosquito in this scenario, but that's is the only scheduling job framework i know and works excellent.
Don't use polling. Instead, set up a timer task, set it to fire at midnight, and add an event to process.
TimeSpan timeBetween = DateTime.Today.AddDays(1) - DateTime.Now;
System.Timers.Timer t = new System.Timers.Timer();
t.Elapsed += new System.Timers.ElapsedEventHandler(t_Elapsed);
t.Interval = 1000 * timeBetween.Seconds;
t.Start();
I'm a little confuse about why you need a WinForm, will it be running at midnight? If all you need is some sort process to run, use the windows scheduler to run it at midnight. (On XP, but I believe Win server should be similar)Control Panel -> Scheduled Tasks -> Add Scheduled Task -> Fill out the wizard. Save you a lot of coding.
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