Stopwatch Timer 时间 计时器 ElapsedMilliseconds

/// <summary>
/// 转换成时间 00:00:00
/// </summary>
/// <param name="duration"></param>
/// <returns></returns>
public string time(long duration)
{
    TimeSpan t = new TimeSpan(0, 0, Convert.ToInt32(duration));
    //string str = "00:00:00";
    return   $"{t.Hours:00}:{t.Minutes:00}:{t.Seconds : 00}";
}

int t = 0;
private void timer1_Tick(object sender, EventArgs e)
{
    t++;
    label4.Text =$"时间:{time(t)}";
}

(sw.ElapsedMilliseconds / 1000f).ToString("0.000 sec")