C#时间计算

long sql_server_run_time_in_milli_seconds = 2020202020202; //毫秒

DateTime sql_server_start = DateTime.Now - TimeSpan.FromMilliseconds(sql_server_run_time_in_milli_seconds);

label12.Text = "启动时间：" + sql_server_start.ToString("yyyy/MM/dd HH:mm:ss", DateTimeFormatInfo.InvariantInfo);

//以秒为单位

DateTime mysql_startup_time = DateTime.Now - TimeSpan.FromSeconds(mysql_start_time_l);

label16.Text = "启动时间：" + mysql_startup_time.ToString("yyyy/MM/dd HH:mm:ss", DateTimeFormatInfo.InvariantInfo);