ProcessHelper_EnsureSingleInsance

using System;
using System.Diagnostics;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

namespace Core.System.Diagnostics {

    public static class ProcessHelper {

        const int SW_RESTORE = 9;

        [DllImport("user32.dll",EntryPoint = "SetForegroundWindow")]
        public static extern bool SetForegroundWindow(IntPtr hWnd);

        [DllImport("user32.dll")]
        public static extern Boolean ShowWindow(IntPtr hWnd,Int32 nCmdShow);

        /// <summary>
        /// Ensures a process single insance
        /// </summary>
        /// <param name="mainWidowTitle">Main widow title</param>
        /// <returns>True if the same process is already running</returns>
        public static bool EnsureSingleInsance(string mainWidowTitle,bool focusRunningApp = true) {

            Process current = Process.GetCurrentProcess();

            //get active title if no main title
            if(Form.ActiveForm != null)
                mainWidowTitle = Form.ActiveForm.Text;

            //find process
            Process alreadyRunning = Process.GetProcessesByName(current.ProcessName)
                .Where(p => {
                    try {
                        if(p.MainWindowTitle.StartsWith(mainWidowTitle)) {
                            return p.MainModule.FileName == current.MainModule.FileName;
                        }
                        return false;
                    }
                    catch {
                        return false;
                    }
                })
                .FirstOrDefault();

            //show existing process
            if(alreadyRunning != null) {
                if(focusRunningApp) {
                    IntPtr handle = alreadyRunning.MainWindowHandle;
                    ShowWindow(handle,SW_RESTORE);
                    SetForegroundWindow(handle);
                }
                return false;
            }
            return true;
        }
    }
}