C# 定时器类 Change(dueDate, period)

Question

i have go through the msdn library about this timer class change function ,

http://msdn.microsoft.com/en-us/library/yz1c7148.aspx

public bool Change( int dueTime, int period )

But i do not understand what is the period parameter for.

i also try to create a sample to see what it for but seems like it is doing nothing

Timer JobTime = new Timer(timer =>
        {
            try
            {
                WriteLog(DateTime.Now.ToString(), "TestJobTimer"); //Save invoke time to file

                ((Timer)timer).Change(TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(20));
            }
            catch(Exception ex)
            {
                string stop = ex.Message;
            }
        });
        JobTime.Change(0, 0);

Base on this sample , what i get is the timer will repeat every 5 second , thus what is the PERIOD paramenter for ?

Thank you

Answer 1

shows when the first event will be fired,

how often after that

in your case the first event will be fired after 5 second then after every 20 seconds

EDIT

As far as you are calling your timer change with 0,0, it starts impatiently and on timer tick call you change it to fire after 5 seconds every 20 second, that's why event fires every 5 seconds

If you want to fire event every 20 seconds after 5 seconds, remove timer change from handler, and start timer only once like this

    Timer JobTime = new Timer(timer =>
    {
        try
        {
            Console.WriteLine(DateTime.Now.ToString(), "TestJobTimer"); //Save invoke time to file
        }
        catch (Exception ex)
        {
            string stop = ex.Message;
        }
    });
    JobTime.Change(TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(20));

Hope this helps

Answer 2

DueTime = time until first deployment

Period = amount of time after due time for next deployment, and amount of time for each subsequent deployment.