如何完成一个具有Pause和Continue这两个功能的Windows Service

 

如何实现一个Windows Service，我以前有篇文章进行介绍过，具体地址如下，如果想做这方面程序的话，可以先看它。

http://blog.csdn.net/knight94/archive/2006/03/17/627298.aspx

 

但是对于一个Windows Service来说，经常是24小时运行，那么难免有时会进行类似于Pause，Continue，Stop以及Restart之类的操作。也就是如何让自己写得Windows Service也能完成类似功能。

 

那么首先分析，对于一个24小时运行的Service来说，必定有子线程的支撑，那么对于Service的相应操作要转化到子线程中，那么我原先的文章对于此处有些问题，在此用一个更好的方法来更新它。

 

首先，介绍子线程类，完整代码如下。

//--------------------------- Sub-thread class ---------------------------------------

//------------------------------------------------------------------------------------

//---File:          clsSubThread

//---Description:   The sub-thread class file to demenstrate howto suspend or resume

//                  a thread

//---Author:        Knight

//---Date:          Aug.21, 2006

//------------------------------------------------------------------------------------

//---------------------------{Sub-thread class}---------------------------------------

namespace WinSDemo

{

    using System;

    using System.Threading;

    using System.IO;

    /// <summary>

    /// Summary description for clsSubThread.

    /// </summary>

    public class clsSubThread

    {

        private Thread thdSubThread = null;

        private Mutex mUnique = new Mutex();

 

        private bool blnIsStopped;

        private bool blnSuspended;

        private bool blnStarted;

 

        public bool IsStopped

        {

            get{ return blnIsStopped; }

        }

        public bool IsSuspended

        {

            get{ return blnSuspended; }

        }

 

   

        public clsSubThread()

        {

            //

            // TODO: Add constructor logic here

            //

            blnIsStopped = true;

            blnSuspended = false;

            blnStarted = false;

        }

 

        /// <summary>

        /// Start sub-thread

        /// </summary>

        public void Start()

        {

            if( !blnStarted )

            {

                thdSubThread = new Thread( new ThreadStart( SubThread ) );

                blnIsStopped = false;

                blnStarted = true;

                thdSubThread.Start();

            }

        }

 

        /// <summary>

        /// Thread entry function

        /// </summary>

        private void SubThread()

        {

            do

            {

                // Wait for resume-command if got suspend-command here 

                mUnique.WaitOne();

                mUnique.ReleaseMutex();

 

                try

                {

                    using( StreamWriter sw = new StreamWriter("c://MyLog.txt",true) )

                    {

                        sw.WriteLine( DateTime.Now.ToString() );

                        sw.Close();

                    }

                }

                catch{};

           

                Thread.Sleep(1000);

            }while( blnIsStopped == false );

        }

 

        /// <summary>

        /// Suspend sub-thread

        /// </summary>

        public void Suspend()

        {

            if( blnStarted && !blnSuspended )

            {

                blnSuspended = true;

                mUnique.WaitOne();

            }

        }

   

        /// <summary>

        /// Resume sub-thread

        /// </summary>

        public void Resume()

        {

            if( blnStarted && blnSuspended )

            {

                blnSuspended = false;

                mUnique.ReleaseMutex();

            }

        }

 

        /// <summary>

        /// Stop sub-thread

        /// </summary>

        public void Stop()

        {

            if( blnStarted )

            {

                if( blnSuspended )

                    Resume();

 

                blnStarted = false;

                blnIsStopped = true;

                thdSubThread.Join();

            }

        }

 

    }

}

 

接着就是要修改Windows程序中的调用。

修改一，定义局部成员；

private clsSubThread mySubThread = null;

 

修改二，在InitializeComponent中初始化局部成员；

    // Init sub-thread object here

    mySubThread = new clsSubThread();

 

其次，就是Service定义的事件方法；

        /// <summary>

        /// Set things in motion so your service can do its work.

        /// </summary>

        protected override void OnStart(string[] args)

        {

            // TODO: Add code here to start your service.

 

            mySubThread.Start();

        }

 

        /// <summary>

        /// Stop this service.

        /// </summary>

        protected override void OnStop()

        {

            // TODO: Add code here to perform any tear-down necessary to stop your service.

            mySubThread.Stop();

        }

 

        protected override void OnPause()

        {

            mySubThread.Suspend();

        }

 

        protected override void OnContinue()

        {

            mySubThread.Resume();

        }

 

把如上的修改操作在原先的例子上，一个能Pause和Continue的Service就完成了。