Xin chào các bạn, bài viết hôm nay mình tiếp tục hướng dẫn các bạn cách thay đổi text button trên MessageBox C# Winform, để đồng bộ hóa giao diện.

[C#] How to change text button in MessageBox Winform

Trên MessageBox winform, các bạn có thể thay đổi tiêu đề và nội dung.

Nhưng các nút hành động như: OK, Yes, No, Cancel Abort, Ignore...

Thì mặc định các bạn không thể thay đổi được.

Giao diện demo ứng dụng:

Ở hình trên, các bạn thấy mình đã thay đổi 3 nút button.

Các bước thực hiện:

Đầu tiên, các bạn tạo cho mình một class MessageBoxManager.cs

#pragma warning disable 0618
using System;
using System.Text;
using System.Runtime.InteropServices;
using System.Security.Permissions;
using System.Diagnostics;

[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;
        private const int MBSave = 1038;
        private const int MBOpen = 9;


        [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;

        public static string OK = "&OK";
        public static string Cancel = "&Cancel";
        public static string Abort = "&Abort";
        public static string Retry = "&Retry";
        public static string Ignore = "&Ignore";
        public static string Yes = "&Yes";
        public static string No = "&No";

        public static string Save = "&Save";

        public static string Open = "&Open";

        static MessageBoxManager()
        {
            hookProc = new HookProc(MessageBoxHookProc);
            enumProc = new EnumChildProc(MessageBoxEnumProc);
            hHook = IntPtr.Zero;
        }

        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());
        }

        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;
                    case MBSave:
                        SetWindowText(hWnd, Save);
                        break;
                    case MBOpen:
                        SetWindowText(hWnd, Open);
                        break;


                }
                nButton++;
            }

            return true;
        }


    }
}

Ở file program.cs, các bạn tiến hành thay đổi các chữ của button theo ý bạn.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CustomTextMessageBox
{
    internal static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            MessageBoxManager.OK = "Đồng ý";
            MessageBoxManager.Cancel = "Đóng";
            MessageBoxManager.Yes = "Vâng";
            MessageBoxManager.No = "Không";
            MessageBoxManager.Save = "Lưu lại";
            MessageBoxManager.Abort = "Lưu lại";
            MessageBoxManager.Register();
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
            MessageBoxManager.Unregister();
        }
    }
}

Chúc các bạn thành công.

Thanks for watching!

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