学步园

        #region 保证程序单实例运行  modified by ychh
        private const int WS_SHOWNORMAL = 1;

        public const Int32 AW_BLEND = 0x00080000;
        [DllImport("User32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);
        [DllImport("User32.dll")]
        private static extern bool SetForegroundWindow(IntPtr hWnd);
        [DllImport("User32.dll")]
        private static extern bool AnimateWindow(IntPtr hwnd, int dwTime, int dwFlags);
        [DllImport("User32.dll", EntryPoint = "FindWindow")]
        private extern static IntPtr FindWindow(string lpClassName, string lpWindowName);

        public static Process GetRunningInstance()
        {
            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;
        }

        public static void HandleRunningInstance(Process instance)
        {
            if (instance != null && instance.MainWindowHandle.ToInt32() != 0)
            {
                //MessageBox.Show(instance.MainWindowHandle.ToInt32().ToString());
                string windowTile = instance.MainWindowTitle.Trim();
                if (windowTile == "广东省林业有害生物管理信息系统")
                    ShowWindowAsync(instance.MainWindowHandle, 3);
                else
                    ShowWindowAsync(instance.MainWindowHandle, 1);
                SetForegroundWindow(instance.MainWindowHandle);
            }
            else
            {
                IntPtr hwnd = FindWindow(null, "广东省林业有害生物管理信息系统");
                if (hwnd.ToInt32() == 0)
                {
                    hwnd = FindWindow(null, "用户登录");
                    ShowWindowAsync(hwnd, 1);
                    SetForegroundWindow(hwnd);
                }
                else
                {
                    ShowWindowAsync(hwnd, 3);
                    SetForegroundWindow(hwnd);
                }
            }
        }
        #endregion