Display time elapsed

Question

I need to display the elapsed time dynamically. My code will pop up a message based on an interval value.

public void button1_Click(object sender, EventArgs e)
{         


        

Answer 1

You should store end-time in a filed at form level and then in Tick event handler of the timer check the difference between the end-time and now and update a label which you want to show count-down timer:

private DateTime endTime;
System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
private void button1_Click(object sender, EventArgs e)
{
    var minutes = 0;
    if (int.TryParse(textBox1.Text, out minutes) && timer.Enabled == false)
    {
        endTime = DateTime.Now.AddMinutes(minutes);
        timer.Interval = 1000;
        timer.Tick -= new EventHandler(timer_Tick);
        timer.Tick += new EventHandler(timer_Tick);
        timer.Start();
        UpdateText();
    }
}
void timer_Tick(object sender, EventArgs e)
{
    UpdateText();
}
void UpdateText()
{
    var diff = endTime.Subtract(DateTime.Now);
    if (diff.TotalSeconds > 0)
        label1.Text = string.Format("{0:D2}:{1:D2}:{2:D2}",
                                   diff.Hours, diff.Minutes, diff.Seconds);
    else
    {
        this.Text = "00:00:00";
        timer.Enabled = false;
    }
}