使windows应用程序单实例运行（C#）

 

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

namespace RPAMessenger
...{
    public class Program
    ...{
        private const int WS_SHOWNORMAL = 1;
        [DllImport("User32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);
        [DllImport("User32.dll")]
        private static extern bool SetForegroundWindow(IntPtr hWnd);

        [STAThread]
        static void Main()
        ...{
            //Mutex mutex = new Mutex(false, "RPAMessenger");
            //bool Running = !mutex.WaitOne(0, false);
            //if (!Running)
            //{
            //    Application.EnableVisualStyles();
            //    Application.SetCompatibleTextRenderingDefault(false);
            //    Application.Run(new FrmRPAMsgLgn());
            //}
            //else
            //{ }
            Process instance = GetRunningInstance();
            if (instance == null)
            ...{
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new FrmRPAMsgLgn());
            }
            else
            ...{
                HandleRunningInstance(instance);
            }
        }

        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)
        ...{
            ShowWindowAsync(instance.MainWindowHandle, WS_SHOWNORMAL);
            SetForegroundWindow(instance.MainWindowHandle);
        }
    }
}