c# windows service 实现监控其他程序是否被关闭,关闭则报警

 namespace MonitorService
 {
     public partial class MonitorSv : ServiceBase
     {
         string AppName = "",MusicName = "";
         string apppath = "";
         Thread threadwork;
         SoundPlayer player;
         public MonitorSv()
         {
             InitializeComponent();
             string path = Directory.GetCurrentDirectory()+"\\Resources\\XML\\AppFile.xml";// Directory.GetCurrentDirectory() + "\\Resources\\XML\\AppFile.xml";
             string[] names = RwXmlBs.ReadXml(path);
             if (names != null && names.Length == )
             this.AppName = names[];
             this.MusicName = names[];
             //Beep(1000, 10000);//调试可以响,但是安装后不响,所以改成播放声音

             //WriteFile(names[0] + "<=>" + names[1] + "++path:" + path, 0, "构造函数");
             PlayMusic();

         }

         private void PlayMusic()
         {
             if (String.IsNullOrEmpty(MusicName))
                 return;
             player = new SoundPlayer();
             player.SoundLocation = @"D:\\spring.wav";// MusicName;// @""+ MusicName + "";
             player.Load(); //同步加载声音
             player.Play(); //启用新线程播放
         }

         private void PlayerStop()
         {
             if (player != null)
             {
                 player.Stop();
             }
         }
         protected override void OnStart(string[] args)
         {
             if (threadwork == null)
             {
                 threadwork = new Thread(CheckAppMethod);
                 threadwork.IsBackground = true;
                 threadwork.Start();
             }
         }

         private void CheckAppMethod()
         {
             Process[] ps = null;
             try
             {
                 while (true)
                 {
                     if (!String.IsNullOrEmpty(AppName))
                     {
                         ps = Process.GetProcessesByName(AppName); // "MakeCard"); //不用带.exe
                         if (ps.Length <= )//进程被杀死,则报警.
                         {
                             PlayMusic();
                             //Been(500,1000);//不可以响,搞不懂
                         }
                         else
                         {
                             PlayerStop();
                         }
                     }
                     System.Threading.Thread.Sleep();
                 }
             }
             catch (Exception EX)
             {
                 WriteFile(AppName, ps.Length, "异常的"+EX.ToString());
                 OnShutdown();
             }
         }

         private void WriteFile(string AppName,int Length, string EX)
         {
             try
             {
                 FileStream fs = new FileStream(apppath+"\\CloseFileLog.txt", FileMode.OpenOrCreate, FileAccess.Write);
                 StreamWriter sw = new StreamWriter(fs);
                 sw.BaseStream.Seek(, SeekOrigin.End);
                 sw.WriteLine("AppName:" + AppName + "++ps.Length:" + Length + ">>>" + DateTime.Now.ToString() + EX.ToString() + "\n");
                 sw.Flush();
                 sw.Close();
                 fs.Close();
             }
             catch (Exception ex)
             {

             }
         }

         protected override void OnShutdown()
         {
             base.OnShutdown();
         }

         protected override void OnStop()
         {
             GC.Collect();
             PlayerStop();
         }

         // 第一个参数是指频率的高低，越大越高，第二个参数是指响的时间多长
      [DllImport("kernel32.dll", EntryPoint = "Beep")]
      public static extern int Beep(int dwFreq,int dwDuration);
     }
 }