SendKey command C#

Question

Hi there! I will be grateful to anybody who could help!

I'm using the InterceptKeys class below to change some of the keys. For example when I type the open bracket key "[", I want to change this to "ë" (whenever I type in my computer, not a particular program). I use a SendKey.Send("ë"); whenever the "[" is typed, but the problem is that after "ë" alsot the "[" is typed. Is it possible to replace the "[" with "ë" or any key, or cancel the "[" and just send "ë"?

---

class InterceptKeys
{
    private const int WH_KEYBOARD_LL = 13;
    private const int WM_KEYDOWN = 0x0100;
    private static LowLevelKeyboardProc _proc = HookCallback;
    private static IntPtr _hookID = IntPtr.Zero;

    public static void Main()
    {
        _hookID = SetHook(_proc);
        Application.Run();
        UnhookWindowsHookEx(_hookID);
    }

    private static IntPtr SetHook(LowLevelKeyboardProc proc)
    {
        using (Process curProcess = Process.GetCurrentProcess())
        using (ProcessModule curModule = curProcess.MainModule)
        {
            return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
                GetModuleHandle(curModule.ModuleName), 0);
        }
    }

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

    private static IntPtr HookCallback(
        int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
        {
            int vkCode = Marshal.ReadInt32(lParam);
            //Console.WriteLine((Keys)vkCode);
            if (vkCode == (int)Keys.OemOpenBrackets))
            {

                SendKeys.Send("ë");                   

            }
        }

        return CallNextHookEx(_hookID, nCode, wParam, lParam);
    }

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook,
        LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
        IntPtr wParam, IntPtr lParam);

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr GetModuleHandle(string lpModuleName);
}

---

Answer 1

Return 1 if you handled the key instead of calling CallNextHookEx.

IE, HookCallback() should look like this

private static IntPtr HookCallback(
    int nCode, IntPtr wParam, IntPtr lParam)
{
    if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
    {
        int vkCode = Marshal.ReadInt32(lParam);
        //Console.WriteLine((Keys)vkCode);
        if (vkCode == (int)Keys.OemOpenBrackets))
        {

            SendKeys.Send("ë");                   
            return 1;
        }
    }

    return CallNextHookEx(_hookID, nCode, wParam, lParam);
}