Local windows hooks and CBT hook wrapper

Hooks.cs

//Based on https://docs.microsoft.com/en-us/archive/msdn-magazine/2002/october/cutting-edge-windows-hooks-in-the-net-framework
using System;
using System.Runtime.InteropServices;
using System.Text;

namespace Example
{
    public class HookEventArgs : EventArgs
    {
        #region Properties

        public int HookCode { get; set; }
        public IntPtr LParam { get; set; }
        public IntPtr WParam { get; set; }

        #endregion
    }

    // Windows Hook Types 
    public enum HookType
    {
        WH_JOURNALRECORD = 0,
        WH_JOURNALPLAYBACK = 1,
        WH_KEYBOARD = 2,
        WH_GETMESSAGE = 3,
        WH_CALLWNDPROC = 4,
        WH_CBT = 5,
        WH_SYSMSGFILTER = 6,
        WH_MOUSE = 7,
        WH_HARDWARE = 8,
        WH_DEBUG = 9,
        WH_SHELL = 10,
        WH_FOREGROUNDIDLE = 11,
        WH_CALLWNDPROCRET = 12,
        WH_KEYBOARD_LL = 13,
        WH_MOUSE_LL = 14
    }

    public class LocalWindowsHook
    {
        private readonly HookProc m_filterFunc;
        private readonly HookType m_hookType;

        private IntPtr hookHandle = IntPtr.Zero;

        #region Events

        public event EventHandler<HookEventArgs> HookInvoked;

        #endregion

        #region Constructors

        public LocalWindowsHook(HookType hook)
        {
            m_hookType = hook;
            m_filterFunc = CoreHookProc;
        }

        #endregion

        #region Methods

        public int CoreHookProc(int code, IntPtr wParam, IntPtr lParam)
        {
            if (code < 0)
            {
                return CallNextHookEx(hookHandle, code, wParam, lParam);
            }

            HookEventArgs e = new HookEventArgs {WParam = wParam, HookCode = code, LParam = lParam};
            OnHookInvoked(e);
            return CallNextHookEx(hookHandle, code, wParam, lParam);
        }


        public bool Install()
        {
            hookHandle = SetWindowsHookEx(m_hookType, m_filterFunc, IntPtr.Zero, AppDomain.GetCurrentThreadId());
            return hookHandle != IntPtr.Zero;
        }

        public void Uninstall()
        {
            UnhookWindowsHookEx(hookHandle);
        }

        #endregion

        #region PInvoke

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

        private void OnHookInvoked(HookEventArgs e)
        {
            HookInvoked?.Invoke(this, e);
        }

        [DllImport("user32.dll")]
        private static extern IntPtr SetWindowsHookEx(HookType code, HookProc func, IntPtr hInstance, int threadID);

        [DllImport("user32.dll")]
        private static extern int UnhookWindowsHookEx(IntPtr hhook);

        private delegate int HookProc(int code, IntPtr wParam, IntPtr lParam);

        #endregion
    }

    public class LocalCbtHook : LocalWindowsHook
    {
        #region Events

        public event EventHandler<CbtEventArgs> WindowCreated;
        public event EventHandler<CbtEventArgs> WindowDestroyed;
        public event EventHandler<CbtEventArgs> WindowActivated;
        public event EventHandler<CbtEventArgs> KeyboardFocusGained;

        #endregion

        #region Constructors

        public LocalCbtHook() : base(HookType.WH_CBT)
        {
            HookInvoked += CbtHookInvoked;
        }

        #endregion

        #region Methods

        protected virtual void OnSetFocus(CbtEventArgs focusGainedEventArgs, CbtEventArgs focusLostEventArgs)
        {
            KeyboardFocusGained?.Invoke(this, focusGainedEventArgs);
        }

        protected virtual void OnWindowActivated(CbtEventArgs e)
        {
            WindowActivated?.Invoke(this, e);
        }

        // Helper functions that fire events by executing user code
        protected virtual void OnWindowCreated(CbtEventArgs e)
        {
            WindowCreated?.Invoke(this, e);
        }

        protected virtual void OnWindowDestroyed(CbtEventArgs e)
        {
            WindowDestroyed?.Invoke(this, e);
        }

        private void CbtHookInvoked(object sender, HookEventArgs e)
        {
            CbtHookAction code = (CbtHookAction) e.HookCode;

            switch (code)
            {
                case CbtHookAction.HCBT_CREATEWND:
                    OnWindowCreated(CreateEventArgs(e.WParam));
                    break;
                case CbtHookAction.HCBT_DESTROYWND:
                    OnWindowDestroyed(CreateEventArgs(e.WParam));
                    break;
                case CbtHookAction.HCBT_ACTIVATE:
                    OnWindowActivated(CreateEventArgs(e.WParam));
                    break;
                case CbtHookAction.HCBT_SETFOCUS:
                    OnSetFocus(CreateEventArgs(e.WParam), CreateEventArgs(e.LParam));
                    break;
            }
        }

        // Read and store some information about the window
        private CbtEventArgs CreateEventArgs(IntPtr wParam)
        {
            CbtEventArgs e = new CbtEventArgs();
            // Set the window handle
            e.Handle = wParam;

            // Set the window's class name
            StringBuilder sb1 = new StringBuilder();
            sb1.Capacity = 40;
            GetClassName(e.Handle, sb1, 40);
            e.ClassName = sb1.ToString();

            // Set the window's title bar
            StringBuilder sb2 = new StringBuilder();
            sb2.Capacity = 256;
            GetWindowText(e.Handle, sb2, 256);
            e.Title = sb2.ToString();

            // Cache the dialog flag
            e.IsDialogWindow = e.ClassName == "#32770";

            return e;
        }

        #endregion


        #region Hook actions

        // CBT hook actions
        private enum CbtHookAction
        {
            HCBT_MOVESIZE = 0,
            HCBT_MINMAX = 1,
            HCBT_QS = 2,
            HCBT_CREATEWND = 3,
            HCBT_DESTROYWND = 4,
            HCBT_ACTIVATE = 5,
            HCBT_CLICKSKIPPED = 6,
            HCBT_KEYSKIPPED = 7,
            HCBT_SYSCOMMAND = 8,
            HCBT_SETFOCUS = 9
        }

        #endregion


        #region PInvoke

        // Win32: GetClassName
        [DllImport("user32.dll")]
        protected static extern int GetClassName(IntPtr hwnd,
                                                 StringBuilder lpClassName, int nMaxCount);

        // Win32: GetWindowText
        [DllImport("user32.dll")]
        protected static extern int GetWindowText(IntPtr hwnd,
                                                  StringBuilder lpString, int nMaxCount);

        #endregion
    }

    public class CbtEventArgs : EventArgs
    {
        #region Properties

        public string ClassName { get; set; }
        public IntPtr Handle { get; set; }
        public bool IsDialogWindow { get; set; }
        public string Title { get; set; }

        #endregion

        #region Methods

        public override string ToString()
            => $"{nameof(Handle)}: 0x{Handle.ToInt64():X}, {nameof(Title)}: {Title}, {nameof(ClassName)}: {ClassName}, {nameof(IsDialogWindow)}: {IsDialogWindow}";

        #endregion
    }
}