winform只运行一个实例

  
                //只运行一个实例
                Process instance = RunningInstance();
                if (instance == null)
                {
                    //1.1 没有实例在运行
                   //new new form1（）为要打开的主窗体
                    Application.Run（new form1（）);
                }
                else
                {
                    //1.2 已经有一个实例在运行
                    HandleRunningInstance(instance);
                }



 #region 确保程序只运行一个实例
        private static Process RunningInstance()
        {
            Process current = Process.GetCurrentProcess();
            Process[] processes = Process.GetProcessesByName(current.ProcessName);
            //遍历与当前进程名称相同的进程列表 
            foreach (Process process in processes)
            {
                //如果实例已经存在则忽略当前进程 
                if (process.Id != current.Id)
                {
                    //保证要打开的进程同已经存在的进程来自同一文件路径
                    if (System.Reflection.Assembly.GetExecutingAssembly().Location.Replace("/", "\\") == current.MainModule.FileName)