NativeM.cs

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

namespace EN2NGui
{
    internal static class NativeM
    {
        internal const int CTRL_C_EVENT = 0;
        [DllImport("kernel32.dll")]
        internal static extern bool GenerateConsoleCtrlEvent(uint dwCtrlEvent, uint dwProcessGroupId);
        [DllImport("kernel32.dll", SetLastError = true)]
        internal static extern bool AttachConsole(uint dwProcessId);
        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
        internal static extern bool FreeConsole();
        [DllImport("kernel32.dll")]
        internal static extern bool SetConsoleCtrlHandler(ConsoleCtrlDelegate HandlerRoutine, bool Add);
        // Delegate type to be used as the Handler Routine for SCCH
        internal delegate Boolean ConsoleCtrlDelegate(uint CtrlType);

        [DllImport("user32")]
        public static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);

        [DllImport("user32")]
        public static extern bool EnableMenuItem(IntPtr hMenu, uint itemId, uint uEnable);

        public static void DisableCloseButton(Form form)
        {
            // The 1 parameter means to gray out. 0xF060 is SC_CLOSE.
            EnableMenuItem(GetSystemMenu(form.Handle, false), 0xF060, 1);
        }

        public static void EnableCloseButton(Form form)
        {
            // The zero parameter means to enable. 0xF060 is SC_CLOSE.
            EnableMenuItem(GetSystemMenu(form.Handle, false), 0xF060, 0);
        }
    }
}