simulate Alt-Enter in parent console from windows app

Program.cs

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;

namespace PaulBettsWIN32
{
    static class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            runTest();
        }

        private static void runTest()
        {
            uint pid = 0x0ffffffff; //ATTACH_PARENT_PROCESS 
            try
            {
                var image = NativeMethods.GetImagePathForPid(pid);

                if (!executableUsesWin32Subsystem(image))
                {
                    if (!NativeMethods.AttachConsole(pid))
                    {
                        var f = new Win32Exception();
                        throw f;
                    }
                    var hStdOut = NativeMethods.GetStdHandle(-11);
                    if (!NativeMethods.SetConsoleDisplayMode(hStdOut, 1, IntPtr.Zero))
                    {
                        var f = new Win32Exception();
                        throw f;
                    }
                    NativeMethods.FreeConsole();
                    return;
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
                throw;
            }
        }

        private static bool executableUsesWin32Subsystem(object o)
        {
            return false;
        }
    }

    public static class NativeMethods
    {
        public static bool GetImagePathForPid(uint pid)
        {
            return true;
        }

        [DllImport("kernel32", SetLastError = true)]
        public static extern bool FreeConsole();

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool AttachConsole(uint dwProcessId);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern IntPtr GetStdHandle(int nStdHandle);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool SetConsoleDisplayMode(
        IntPtr ConsoleOutput,
        uint Flags,
        IntPtr whoKnows);
    }
}