Introduction

        Sometimes we need to run an operation periodically, there are many ways to do that but here I am going to show you how to do that on thread pool using Timer.

Implementation

        See code below:

static void TimerOperation(DateTime start)
{
    TimeSpan elapsed = DateTime.Now - start;
    Console.WriteLine("It has been {0} seconds after {1}. This Thread Pool Id: {2}", elapsed, start, Thread.CurrentThread.ManagedThreadId);
}

Above we created a TimerOperation method which prints elapsed time and thread pool id. Now we need to call this method periodically.

static Timer timer;
static void Main(string[] args)
{
    Console.WriteLine("Press 'Enter' to stop execution...");
    DateTime start = DateTime.Now;
    timer = new Timer(_ => TimerOperation(start), null, 1000, 2000);
    Thread.Sleep(5000);
    timer.Change(500, 100);
    Console.ReadLine();
    timer.Dispose();
}

Above we created object of timer in Main method, 1000ms is due time means after 1 second thread will start execution and 2000 is period in that interval timer will execute TimerOperation method periodically. Change method can change values of due time and period and Dispose is used to dispose timer and stop execution. We can use Timeout.Infinite instead of period if we want TimerOperation to be executed only once. Output will be like: