C#只提供Timer定时器（C++ SetTimer 类似），通过设置一个时间间隔来定时触发执行任务。那么定点执行任务怎么实现呢？

	
	

		
		

			
			

				using System;
			

		

	

	

		
		

			
			

				using System.Collections.Generic;
			

		

	

	

		
		

			
			

				using System.ComponentModel;
			

		

	

	

		
		

			
			

				using System.Data;
			

		

	

	

		
		

			
			

				using System.Diagnostics;
			

		

	

	

		
		

			
			

				using System.Linq;
			

		

	

	

		
		

			
			

				using System.ServiceProcess;
			

		

	

	

		
		

			
			

				using System.Text;
			

		

	

	

		
		

			
			

				using System.Timers;
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				namespace PlanDemoService
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				public partial class Service1 : ServiceBase
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				public Service1()
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				InitializeComponent();
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				// 每天执行一次的时间点(最好写在配置中，这里为了方便展示)
			

		

	

	

		
		

			
			

				private string onceDoStr = "18:00";
			

		

	

	

		
		

			
			

				private DateTime onceDoTime;
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				// 定时执行一次 
			

		

	

	

		
		

			
			

				private Timer onceDoTimer = new Timer();
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				/// <summary>
			

		

	

	

		
		

			
			

				/// 定时器触发事件
			

		

	

	

		
		

			
			

				/// </summary>
			

		

	

	

		
		

			
			

				/// <param name="sender"></param>
			

		

	

	

		
		

			
			

				/// <param name="e"></param>
			

		

	

	

		
		

			
			

				private void OnceDoTimer_Elapsed(object sender, ElapsedEventArgs e)
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				UpdateOnceDoTimePeriod();
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				// 更新下次执行间隔
			

		

	

	

		
		

			
			

				SetNextOnceDoInterval();
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				if (DateTime.Now.ToString("HH:mm").CompareTo(onceDoStr.Trim()) >= 0)
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				// 可能由于系统原因导致触发过早的，不执行
			

		

	

	

		
		

			
			

				onceDoMain();
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				/// <summary>
			

		

	

	

		
		

			
			

				/// 设置定时器间隔时间
			

		

	

	

		
		

			
			

				/// </summary>
			

		

	

	

		
		

			
			

				private void SetNextOnceDoInterval()
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				TimeSpan spanNextDay = new TimeSpan(1, 0, 0, 0);
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				if (DateTime.Now < onceDoTime)
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				onceDoTimer.Interval = (onceDoTime - DateTime.Now).TotalMilliseconds;
			

		

	

	

		
		

			
			

				Loger.Log(string.Format("定时任务将于{0}执行一次。", onceDoTime.ToString("yyyy-MM-dd HH:mm:ss")), "PlanDemoService");
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				if (DateTime.Now > onceDoTime)
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				onceDoTimer.Interval = (onceDoTime + spanNextDay - DateTime.Now).TotalMilliseconds;
			

		

	

	

		
		

			
			

				Loger.Log(string.Format("下次定时任务将于{0}执行一次。", (onceDoTime + spanNextDay).ToString("yyyy-MM-dd HH:mm:ss")), "PlanDemoService");
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				/// <summary>
			

		

	

	

		
		

			
			

				/// 更新任务触发时间(按每天最新日期)
			

		

	

	

		
		

			
			

				/// </summary>
			

		

	

	

		
		

			
			

				private void UpdateOnceDoTimePeriod()
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				string[] parts = onceDoStr.Split(':');
			

		

	

	

		
		

			
			

				onceDoTime = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day,
			

		

	

	

		
		

			
			

				int.Parse(parts[0]), int.Parse(parts[1]), 0);
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				/// <summary>
			

		

	

	

		
		

			
			

				/// 任务执行
			

		

	

	

		
		

			
			

				/// </summary>
			

		

	

	

		
		

			
			

				private void onceDoMain()
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				Loger.Log("任务执行！", "PlanDemoService");
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				protected override void OnStart(string[] args)
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				try
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				UpdateOnceDoTimePeriod();
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				catch (Exception e)
			

		

	

	

		
		

			
			

				{
			

		

	

	

		
		

			
			

				Loger.Log("时间配置有误！" + e.Message, "PlanDemoService");
			

		

	

	

		
		

			
			

				throw e;
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				onceDoTimer.Elapsed += new ElapsedEventHandler(OnceDoTimer_Elapsed);
			

		

	

	

		
		

			
			

				SetNextOnceDoInterval();
			

		

	

	

		
		

			
			

				onceDoTimer.Start();
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
			

		

	

	

		
		

			
			

				protected override void OnStop()
			

		

	

	

		
		

			
			

				 {
			

		

	

	

		
		

			
			

				onceDoTimer.Stop();
			

		

	

	

		
		

			
			

				Loger.Log("服务已停止！", "PlanDemoService");
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				}
			

		

	

	

		
		

			
			

				
				

					}
				

			

		

	




	https://blog.csdn.net/zqp2013/article/details/47419619