2009-03-21 只运行一个实例

      对有窗口的程序，控制只运行一个实例比较容易。但对于运行在后台，设置成任务计划的程序来说，要控制只运行一个实例，就要多费点小小功夫。下面分享下我的代码：希望对大家有点帮助。

using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Reflection;

namespace OneInstance
{
    static class Program
    {
        [STAThread]
        static void Main()
        {
            Process instance = RunningInstance();

            if (instance != null)
            {
                return;
            }

            //Start your transaction code here
        }

        public static Process RunningInstance()
        {
            Process current = Process.GetCurrentProcess();
            Process[] processes = Process.GetProcessesByName(current.ProcessName);

            foreach (Process process in processes)
            {
                if (process.Id != current.Id)
                {
                    if (Assembly.GetExecutingAssembly().Location.Replace("/", "\\") ==
                        current.MainModule.FileName)
                    {
                        return process;
                    }
                }
            }

            return null;
        }
    }
}