Question

I want to add functionality to my WinForms so that when it starts a counter starts which will be in hh:mm. I know this can be done using a timer. I have made a time label which displays the current time, but I don’t know how to start the timer when the form is loaded. Is there any method or class for that?

Answer 1

Place Timer component to your form (drag it from ToolBox – it’s imporant, because timer should be registered as form’s component to be disposed correctly when form closes). Set timer’s Interval property to 60000 (that’s equal to one minute). And subscribe to Tick event:

void timer1_Tick(object sender, EventArgs e)
{
    if (endTime < DateTime.Now)
    {
       MessageBox.Show("Time is out!");
       timer1.Stop();
       return;
    }

    timeLabel.Text = (endTime - DateTime.Now).ToString(@"hh\:mm");
}

On Form_Load event handler start timer and save countdown end time:

private DateTime endTime; // field to store end time

void Form1_Load(object sender, EventArgs e)
{
    endTime = DateTime.Now.AddMinutes(120); // set countdown to 120 minutes
    timer1.Start();
}