How to create a timer that starts on a certain condition, and counts to 15 seconds? (C#)

Question

I am creating a C# library, and am looking to create a timer that starts once a certain condition is met. Then, I want the timer to count up to 15 seconds, and once 15 seconds is reached, another action is performed. It would look something like this:

if (condition is met)
{
    //start timer
}

if (timer == 15 seconds)
{
    //do something
    //reset timer for next time that condition is met
}

Any help on how to do this in C# is greatly appreciated!

Answer 1

//using System.Timers;

How to insitantiate:

Timer timer = new Timer(); //Outside the method

Inside the method that the timer subscribes

timer.Elapsed += new ElapsedEventHandler(OnElapsedTime);
timer.Interval = 15000; //number in milisecinds  
timer.Enabled = true;

The OnElapsedTime EventHandler

private async void OnElapsedTime(object source, ElapsedEventArgs e)
{
    //Do Something
}

Notes:

1. It is important to using System.Timers;
2. The event will run every 15000 (15 seconds)
3. Code inside the event handler will be executed automatically (not need for condition).