//DLL 
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace Hook
{
	public delegate IntPtr HookDelegate(int Code, byte wParam, IntPtr lParam); //Делегат для ф-ий-обработчиков хуковских сообщений 

	public class MessageHooker
	{
		#region Win32 API Imports
		[DllImport("User32.Dll")] public static extern bool UnhookWindowsHookEx(IntPtr HookHandle);
		[DllImport("User32.Dll")] public static extern IntPtr SetWindowsHookEx(int HookId, HookDelegate Delegate, long ModuleHandle, int ThreadId);
		[DllImport("User32.Dll")] public static extern IntPtr CallNextHookEx(IntPtr CurrentHookHandle, int Code, int wParam, int lParam);
		#endregion
        public byte key;
		public event KeyEventHandler KeyPress; //событие, генерится,когда сообщение получено и вызван обработчик 
                 	protected IntPtr KeyboardHook = IntPtr.Zero; //HHOOK 
		protected HookDelegate KeyDelegate;
		public MessageHooker()
		{
			KeyDelegate = new HookDelegate(ProcessKeyHook);
		}

		public void SetHook() //Устанавливаем хук 
		{
			long hModule = System.Runtime.InteropServices.Marshal.GetHINSTANCE(System.Reflection.Assembly.GetExecutingAssembly().GetModules()[0]).ToInt64();
		KeyboardHook = SetWindowsHookEx(2 /*WH_KEYBOARD*/ , KeyDelegate, hModule, 0);
				}

		public void KeyboardUnHook() //снимаем хук 
		{
			if (KeyboardHook.ToInt32() != 0)
			{
				UnhookWindowsHookEx(KeyboardHook);
				KeyboardHook = IntPtr.Zero;
			}
		}
                     public IntPtr ProcessKeyHook(int Code, byte wParam, IntPtr lParam) //обработчик отлавливаемых сообщений 
		{
			if(Code==0)
			{
				KeyEventArgs kea = new KeyEventArgs((Keys)wParam); //в дальнейшем игнорируем 
				key=wParam; //получаем  нажатый символ 
				KeyPress(this, kea); //генерим событие нажатия клавиши. В дальнейшем обрабатывается exe'шником, устанавливающем хук 
				
			}
			return Code < 0 ? CallNextHookEx(KeyboardHook, Code, wParam, lParam.ToInt32()) : IntPtr.Zero; //если в системе есть еще хуки, то передаем им управление. 
			
		}
	}
}

 //EXE 
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using Hook;
 
namespace HookSeter
{
	 /// <summary> 
	 /// Summary description for Form1. 
	 /// </summary> 
	public class Form1 : System.Windows.Forms.Form
	{
		 /// <summary> 
		 /// Required designer variable. 
		 /// </summary> 
		private System.ComponentModel.Container components = null;
        private MessageHooker m_MessageHooker = null;
		public void MessageHooker_KeyPress(object Sender, KeyEventArgs e)
		{
			string s=new string((char)m_MessageHooker.key,1); //Получаем нажатый символ 
			
			MessageBox.Show(s);
			
			
		
			
		}

		public Form1()
		{
			
			InitializeComponent();
			
            m_MessageHooker=new MessageHooker();
			m_MessageHooker.SetHook(); //Ставим хук 
			m_MessageHooker.KeyPress += new KeyEventHandler(MessageHooker_KeyPress); //обрабатываем сообщение нажатия 

        }

		 /// <summary> 
		 /// Clean up any resources being used. 
		 /// </summary> 
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
                m_MessageHooker.KeyboardUnHook(); //Снимаем хук 
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		 /// <summary> 
		 /// Required method for Designer support - do not modify 
		 /// the contents of this method with the code editor. 
		 /// </summary> 
		private void InitializeComponent()
		{
			 //  
			 // Form1 
			 //  
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(292, 266);
			this.Name = "Form1";
			this.Opacity = 0.8;
			this.Text = "Form1";

		}
		#endregion

		 /// <summary> 
		 /// The main entry point for the application. 
		 /// </summary> 
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}
	}
}