using System; using System.Collections.Generic; using System.Diagnostics; using System.IO; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ConsoleApp435 { class Program { static int i = 0; static int j = 0; static void Main(string[] args) { Task t1 = Task.Run(() => { for (int i = 0; i < 10; i++) { WhileStopwatchElapsed(); WhileLoopDatetime(); } }); Console.ReadLine(); } static void WhileStopwatchElapsed() { i = 0; Console.WriteLine("WhileStopwatchElapsed() started!"); Stopwatch sw = new Stopwatch(); sw.Start(); while(sw.Elapsed<TimeSpan.FromSeconds(10)) { i++; } string msg=$"{ DateTime.Now.ToString("yyyyMMddHHmmssffff")},in WhileStopwatchElapsed() i is {i} "; FileWriteMsg(msg); Console.WriteLine(msg); Console.WriteLine("WhileStopwatchElapsed() ended!"); } static void WhileLoopDatetime() { j = 0; Console.WriteLine("WhileLoopDatetime() started!"); var startTime = DateTime.UtcNow; while(DateTime.UtcNow-startTime<TimeSpan.FromSeconds(10)) { j++; } string msg = $"{ DateTime.Now.ToString("yyyyMMddHHmmssffff")},in WhileLoopDatetime() j is {j}"; FileWriteMsg(msg); Console.WriteLine(msg); Console.WriteLine("WhileLoopDatetime() ended!"); } static void FileWriteMsg(string msg) { File.AppendAllText("dt.txt", msg+Environment.NewLine); } } }