c# - Windows 服务的后台 worker

Question

我正在使用 C# 在 Visual Studio 2010 中创建 Windows 服务，我有一些方法，例如 Add、Multiply 和其他方法，我将它们放在 onStart 方法。现在，我希望这些方法每五分钟运行一次。那么后台工作进程如何帮助我呢？

protected override void OnStart(string[] args)
{
    add(); // yes, it doesn't have parameters      
}

Answer 1

计时器是正确的方法。我有一个稍微增强的版本，负责在 OnStop 方法中关闭计时器。

在您的 program.cs 中，我将执行以下操作以简化调试:

using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading;

namespace SampleWinSvc
{
  static class Program
  {
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    static void Main()
    {
#if (!DEBUG)
      ServiceBase[] ServicesToRun;
      ServicesToRun = new ServiceBase[] { new Service1() };
      ServiceBase.Run(ServicesToRun);
#else
      //Debug code: this allows the process to run 
      // as a non-service. It will kick off the
      // service start point, and then run the 
      // sleep loop below.
      Service1 service = new Service1();
      service.Start();
      // Break execution and set done to true to run Stop()
      bool done = false;
      while (!done)
        Thread.Sleep(10000);
      service.Stop();
#endif
    }
  }
}

然后，在您的 Service1.cs 代码中:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Timers;
using System.Text;

namespace SampleWinSvc
{
    public partial class Service1 : ServiceBase
    {
        /// <summary>
        /// This timer willl run the process at the interval specified (currently 10 seconds) once enabled
        /// </summary>
        Timer timer = new Timer(10000);

        public Service1()
        {
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            Start();
        }

        public void Start()
        {
            // point the timer elapsed to the handler
            timer.Elapsed += new ElapsedEventHandler(timer_Elapsed);
            // turn on the timer
            timer.Enabled = true;
        }

        /// <summary>
        /// This is called when the service is being stopped. 
            /// You need to wrap up pretty quickly or ask for an extension.
        /// </summary>
        protected override void OnStop()
        {
            timer.Enabled = false;
        }

            /// <summary>
            /// Runs each time the timer has elapsed. 
            /// Remember that if the OnStop turns off the timer, 
            /// that does not guarantee that your process has completed. 
            /// If the process is long and iterative, 
            /// you may want to add in a check inside it 
            /// to see if timer.Enabled has been set to false, or 
            /// provide some other way to check so that 
            /// the process will stop what it is doing.
            /// </summary>
            /// <param name="sender"></param>
            /// <param name="e"></param>
        void timer_Elapsed(object sender, ElapsedEventArgs e)
        {
            MyFunction();
        }

        private int secondsElapsed = 0;
        void MyFunction()
        {
            secondsElapsed += 10;
        }
    }
}

通过在编译选项中设置#DEBUG var，您可以自己运行代码作为一个程序然后当你准备好测试你的关闭逻辑时，简单地打破所有并设置完成为真。多年来我一直在使用这种方法并取得了很大的成功。

如代码中所述，如果您在计时器事件中做任何冗长的事情，那么您可能希望从 OnStop 对其进行监视，以确保它在事情中间关闭时有足够的时间。