#pragma warning disable 0618

using System;

using System.Text;

using System.Runtime.InteropServices;

using System.Security.Permissions;



[assembly: SecurityPermission(SecurityAction.RequestMinimum, UnmanagedCode = true)]

namespace System.Windows.Forms

{

    public class MessageBoxManager

    {

        private delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);

        private delegate bool EnumChildProc(IntPtr hWnd, IntPtr lParam);



        private const int WH_CALLWNDPROCRET = 12;

        private const int WM_DESTROY = 0x0002;

        private const int WM_INITDIALOG = 0x0110;

        private const int WM_TIMER = 0x0113;

        private const int WM_USER = 0x400;

        private const int DM_GETDEFID = WM_USER + 0;



        private const int MBOK = 1;

        private const int MBCancel = 2;

        private const int MBAbort = 3;

        private const int MBRetry = 4;

        private const int MBIgnore = 5;

        private const int MBYes = 6;

        private const int MBNo = 7;





        [DllImport("user32.dll")]

        private static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);



        [DllImport("user32.dll")]

        private static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);



        [DllImport("user32.dll")]

        private static extern int UnhookWindowsHookEx(IntPtr idHook);



        [DllImport("user32.dll")]

        private static extern IntPtr CallNextHookEx(IntPtr idHook, int nCode, IntPtr wParam, IntPtr lParam);



        [DllImport("user32.dll", EntryPoint = "GetWindowTextLengthW", CharSet = CharSet.Unicode)]

        private static extern int GetWindowTextLength(IntPtr hWnd);



        [DllImport("user32.dll", EntryPoint = "GetWindowTextW", CharSet = CharSet.Unicode)]

        private static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int maxLength);



        [DllImport("user32.dll")]

        private static extern int EndDialog(IntPtr hDlg, IntPtr nResult);



        [DllImport("user32.dll")]

        private static extern bool EnumChildWindows(IntPtr hWndParent, EnumChildProc lpEnumFunc, IntPtr lParam);



        [DllImport("user32.dll", EntryPoint = "GetClassNameW", CharSet = CharSet.Unicode)]

        private static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);



        [DllImport("user32.dll")]

        private static extern int GetDlgCtrlID(IntPtr hwndCtl);



        [DllImport("user32.dll")]

        private static extern IntPtr GetDlgItem(IntPtr hDlg, int nIDDlgItem);



        [DllImport("user32.dll", EntryPoint = "SetWindowTextW", CharSet = CharSet.Unicode)]

        private static extern bool SetWindowText(IntPtr hWnd, string lpString);





        [StructLayout(LayoutKind.Sequential)]

        public struct CWPRETSTRUCT

        {

            public IntPtr lResult;

            public IntPtr lParam;

            public IntPtr wParam;

            public uint message;

            public IntPtr hwnd;

        };



        private static HookProc hookProc;

        private static EnumChildProc enumProc;

        [ThreadStatic]

        private static IntPtr hHook;

        [ThreadStatic]

        private static int nButton;



        /// <summary>

        /// OK text

        /// </summary>

        public static string OK = "&OK";

        /// <summary>

        /// Cancel text

        /// </summary>

        public static string Cancel = "&Cancel";

        /// <summary>

        /// Abort text

        /// </summary>

        public static string Abort = "&Abort";

        /// <summary>

        /// Retry text

        /// </summary>

        public static string Retry = "&Retry";

        /// <summary>

        /// Ignore text

        /// </summary>

        public static string Ignore = "&Ignore";

        /// <summary>

        /// Yes text

        /// </summary>

        public static string Yes = "&Yes";

        /// <summary>

        /// No text

        /// </summary>

        public static string No = "&No";



        static MessageBoxManager()

        {

            hookProc = new HookProc(MessageBoxHookProc);

            enumProc = new EnumChildProc(MessageBoxEnumProc);

            hHook = IntPtr.Zero;

        }



        /// <summary>

        /// Enables MessageBoxManager functionality

        /// </summary>

        /// <remarks>

        /// MessageBoxManager functionality is enabled on current thread only.

        /// Each thread that needs MessageBoxManager functionality has to call this method.

        /// </remarks>

        public static void Register()

        {

            if (hHook != IntPtr.Zero)

                throw new NotSupportedException("One hook per thread allowed.");

            hHook = SetWindowsHookEx(WH_CALLWNDPROCRET, hookProc, IntPtr.Zero, AppDomain.GetCurrentThreadId());

        }



        /// <summary>

        /// Disables MessageBoxManager functionality

        /// </summary>

        /// <remarks>

        /// Disables MessageBoxManager functionality on current thread only.

        /// </remarks>

        public static void Unregister()

        {

            if (hHook != IntPtr.Zero)

            {

                UnhookWindowsHookEx(hHook);

                hHook = IntPtr.Zero;

            }

        }



        private static IntPtr MessageBoxHookProc(int nCode, IntPtr wParam, IntPtr lParam)

        {

            if (nCode < 0)

                return CallNextHookEx(hHook, nCode, wParam, lParam);



            CWPRETSTRUCT msg = (CWPRETSTRUCT)Marshal.PtrToStructure(lParam, typeof(CWPRETSTRUCT));

            IntPtr hook = hHook;



            if (msg.message == WM_INITDIALOG)

            {

                int nLength = GetWindowTextLength(msg.hwnd);

                StringBuilder className = new StringBuilder(10);

                GetClassName(msg.hwnd, className, className.Capacity);

                if (className.ToString() == "#32770")

                {

                    nButton = 0;

                    EnumChildWindows(msg.hwnd, enumProc, IntPtr.Zero);

                    if (nButton == 1)

                    {

                        IntPtr hButton = GetDlgItem(msg.hwnd, MBCancel);

                        if (hButton != IntPtr.Zero)

                            SetWindowText(hButton, OK);

                    }

                }

            }



            return CallNextHookEx(hook, nCode, wParam, lParam);

        }



        private static bool MessageBoxEnumProc(IntPtr hWnd, IntPtr lParam)

        {

            StringBuilder className = new StringBuilder(10);

            GetClassName(hWnd, className, className.Capacity);

            if (className.ToString() == "Button")

            {

                int ctlId = GetDlgCtrlID(hWnd);

                switch (ctlId)

                {

                    case MBOK:

                        SetWindowText(hWnd, OK);

                        break;

                    case MBCancel:

                        SetWindowText(hWnd, Cancel);

                        break;

                    case MBAbort:

                        SetWindowText(hWnd, Abort);

                        break;

                    case MBRetry:

                        SetWindowText(hWnd, Retry);

                        break;

                    case MBIgnore:

                        SetWindowText(hWnd, Ignore);

                        break;

                    case MBYes:

                        SetWindowText(hWnd, Yes);

                        break;

                    case MBNo:

                        SetWindowText(hWnd, No);

                        break;



                }

                nButton++;

            }



            return true;

        }





    }

}