C# [WIN32] [API] Global Hook

NativeMethods.cs:

using System;
using System.Runtime.InteropServices;

namespace GlobalHook
{
    internal static class NativeMethods
    {
        #region window message
        internal const int WM_MOUSEMOVE = 0x200;

        internal const int WM_LBUTTONDOWN = 0x201;

        internal const int WM_RBUTTONDOWN = 0x204;

        internal const int WM_MBUTTONDOWN = 0x207;

        internal const int WM_LBUTTONUP = 0x202;

        internal const int WM_RBUTTONUP = 0x205;

        internal const int WM_MBUTTONUP = 0x208;

        internal const int WM_LBUTTONDBLCLK = 0x203;

        internal const int WM_RBUTTONDBLCLK = 0x206;

        internal const int WM_MBUTTONDBLCLK = 0x209;

        internal const int WM_MOUSEWHEEL = 0x020A;
        #endregion

        #region param idHook
        internal const int WH_CALLWNDPROC = ;

        internal const int WH_CALLWNDPROCRET = ;

        internal const int WH_CBT = ;

        internal const int WH_DEBUG = ;

        internal const int WH_FOREGROUNDIDLE = ;

        internal const int WH_GETMESSAGE = ;

        internal const int WH_JOURNALPLAYBACK = ;

        internal const int WH_JOURNALRECORD = ;

        internal const int WH_KEYBOARD = ;

        internal const int WH_KEYBOARD_LL = ;

        internal const int WH_MOUSE = ;

        internal const int WH_MOUSE_LL = ;

        internal const int WH_MSGFILTER = -;

        internal const int WH_SHELL = ;

        internal const int WH_SYSMSGFILTER = ;
        #endregion

        [StructLayout(LayoutKind.Sequential)]
        internal class POINT
        {
            internal int x;
            internal int y;

            internal POINT(int x, int y)
            {
                this.x = x;
                this.y = y;
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        internal class MOUSEHOOKSTRUCT
        {
            internal POINT pt;
            internal IntPtr hWnd;
            internal int wHitTestCode;
            internal int dwExtraInfo;
        }

        [StructLayout(LayoutKind.Sequential)]
        internal class MOUSEHOOKSTRUCTEX
        {
            internal MOUSEHOOKSTRUCT MOUSEHOOKSTRUCT;
            internal uint mouseData;
        }

        internal delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);
    }
}

UnsafeNativeMethods.cs:

using System;
using System.Runtime.InteropServices;
using static GlobalHook.NativeMethods;

namespace GlobalHook
{
    internal static class UnsafeNativeMethods
    {
        /// <summary>
        /// https://msdn.microsoft.com/en-us/library/ms644990(VS.85).aspx        /// </summary>
        /// <param name="idHook"></param>
        /// <param name="lpfn"></param>
        /// <param name="hMod"></param>
        /// <param name="dwThreadId"></param>
        /// <returns></returns>
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall, SetLastError = true)]
        internal static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, HandleRef hMod, int dwThreadId);

        /// <summary>
        /// https://msdn.microsoft.com/en-us/library/ms644993(VS.85).aspx        /// </summary>
        /// <param name="hhk"></param>
        /// <returns></returns>
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall, SetLastError = true)]
        internal static extern bool UnhookWindowsHookEx(HandleRef hhk);

        /// <summary>
        /// https://msdn.microsoft.com/en-us/library/ms644974(VS.85).aspx        /// </summary>
        /// <param name="hhk"></param>
        /// <param name="nCode"></param>
        /// <param name="wParam"></param>
        /// <param name="lParam"></param>
        /// <returns></returns>
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        internal static extern IntPtr CallNextHookEx(HandleRef hhk, int nCode, IntPtr wParam, IntPtr lParam);

        /// <summary>
        /// https://msdn.microsoft.com/en-us/library/ms683199(VS.85).aspx        /// </summary>
        /// <param name="lpModuleName"></param>
        /// <returns></returns>
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        internal static extern IntPtr GetModuleHandle(string lpModuleName);
    }
}

From1.cs:

using System;
using System.Diagnostics;
using System.Drawing;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;
using static GlobalHook.NativeMethods;
using static GlobalHook.SafeNativeMethods;
using static GlobalHook.UnsafeNativeMethods;

namespace GlobalHook
{
    public partial class Form1 : Form
    {
        private IntPtr hook;

        private HookProc mouseHookProcedure;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            UnhookWindowsHookEx(new HandleRef(null, hook));
        }

        private void btnHook_Click(object sender, EventArgs e)
        {
            if (btnHook.Text == "hook")
            {
                mouseHookProcedure = LowLevelMouseProc;
                hook = SetWindowsHookEx(WH_MOUSE_LL, mouseHookProcedure, new HandleRef(null, GetModuleHandle(null)), );
                if (hook != IntPtr.Zero)
                {
                    btnHook.Text = "unhook";
                }
            }
            else
            {
                if (UnhookWindowsHookEx(new HandleRef(null, hook)))
                {
                    btnHook.Text = "hook";
                }
            }
        }

        private IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            MOUSEHOOKSTRUCT mouseHookStruct = Marshal.PtrToStructure<MOUSEHOOKSTRUCT>(lParam);
            switch ((int)wParam)
            {
                case WM_MOUSEMOVE:
                    break;
                case WM_LBUTTONDOWN:
                    break;
                case WM_RBUTTONDOWN:
                    break;
                case WM_MBUTTONDOWN:
                    break;
                case WM_LBUTTONUP:
                    break;
                case WM_RBUTTONUP:
                    break;
                case WM_MBUTTONUP:
                    break;
                case WM_LBUTTONDBLCLK:
                    break;
                case WM_RBUTTONDBLCLK:
                    break;
                case WM_MBUTTONDBLCLK:
                    break;
                case WM_MOUSEWHEEL:
                    break;
                default:
                    break;
            }
            return CallNextHookEx(new HandleRef(null, hook), nCode, wParam, lParam);
        }
    }
}