How do I display a digital timer (StopWatch) in datagridview column dynamically c#?

Question

I have datagridview whose datasource is datatable.

I have two columns in datagridview:

NAME, IN TIME

After the datagridview is loaded, I want to add

Answer 1

You can add a string column to DataTable and use it as duration column. Then you can subscribe to Tick event of a timer which you set it's interval to 1000 and show the result of count down timer in duration column:

void timer_Tick(object sender, EventArgs e)
{
    foreach( DataRow row in YourDataTable.Rows)
    {
        var diff = row.Field("DateTimeColumn").Subtract(DateTime.Now);
        if(diff.TotalSeconds>0)
        {
            row["DurationColumn"] = string.Format("{0} d {1:D2}:{2:D2}:{3:D2}", 
                                       diff.Days, diff.Hours, diff.Minutes, diff.Seconds);
        }
        else
        {
            row["DurationColumn"] = "0 d 00:00:00";
        }
    }
}