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

namespace SIASUN.TwinCatLogger
{
    static class Program
    {
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            //Get the running instance.   
            Process instance = RunningInstance();
            if (instance == null)
            {
                System.IO.Directory.SetCurrentDirectory(Application.StartupPath);
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new MainForm());
            }
            else
            {
                //There is another instance of this process.   
                HandleRunningInstance(instance);
            }
        }

        #region 单实例运行
        public static Process RunningInstance()
        {
            Process current = Process.GetCurrentProcess();
            Process[] processes = Process.GetProcessesByName(current.ProcessName);
            //Loop through the running processes in with the same name
            foreach (Process process in processes)
            {
                //Ignore the   current   process   
                if (process.Id != current.Id)
                {
                    //Make sure that the process is running from the exe file.
                    if (Assembly.GetExecutingAssembly().Location.Replace("/", "//") == current.MainModule.FileName)
                    {
                        //Return the other process instance.
                        return process;
                    }
                }
            }
            //No other instance was found, return null. 
            return null;
        }
        public static void HandleRunningInstance(Process instance)
        {
            //Make sure the window is not minimized or maximized
            ShowWindowAsync(instance.MainWindowHandle, SW_NORMAL);
            //Set the real intance to foreground window
            SetForegroundWindow(instance.MainWindowHandle);
        }
        [DllImport("User32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);
        [DllImport("User32.dll")]
        private static extern bool SetForegroundWindow(IntPtr hWnd);
        private const int SW_HIDE = 0;
        private const int SW_NORMAL = 1;
        private const int SW_MAXIMIZE = 3;
        private const int SW_SHOWNOACTIVATE = 4;
        private const int SW_SHOW = 5;
        private const int SW_MINIMIZE = 6;
        private const int SW_RESTORE = 9;
        private const int SW_SHOWDEFAULT = 10;
        #endregion
    }
}