MouseHook.cs

using System;
using System.Runtime.InteropServices;
using System.Diagnostics;

// Based on MouseHook.cs : https://github.com/rvknth043/Global-Low-Level-Key-Board-And-Mouse-Hook/

namespace GlobalLowLevelHooks {
	/// <summary>
	/// Class for intercepting low level Windows mouse hooks.
	/// </summary>
	public class MouseHook {
		/// <summary>
		/// Internal callback processing function
		/// </summary>
		private delegate IntPtr MouseHookHandler(int nCode, IntPtr wParam, IntPtr lParam);
		private MouseHookHandler hookHandler;

		/// <summary>
		/// Function to be called when defined even occurs
		/// </summary>
		/// <param name="mouseStruct">MSLLHOOKSTRUCT mouse structure</param>
		public delegate void MouseHookCallback(MSLLHOOKSTRUCT mouseStruct);

		#region Events
		public event MouseHookCallback LeftButtonDown;
		public event MouseHookCallback LeftButtonUp;
		public event MouseHookCallback RightButtonDown;
		public event MouseHookCallback RightButtonUp;
		public event MouseHookCallback MouseMove;
		public event MouseHookCallback MouseWheel;
		public event MouseHookCallback DoubleClick;
		public event MouseHookCallback MiddleButtonDown;
		public event MouseHookCallback MiddleButtonUp;
		#endregion

		/// <summary>
		/// Low level mouse hook's ID
		/// </summary>
		private IntPtr hookID = IntPtr.Zero;

		/// <summary>
		/// Install low level mouse hook
		/// </summary>
		/// <param name="mouseHookCallbackFunc">Callback function</param>
		public void Install() {
			hookHandler = HookFunc;
			hookID = SetHook(hookHandler);
		}

		/// <summary>
		/// Remove low level mouse hook
		/// </summary>
		public void Uninstall() {
			if (hookID == IntPtr.Zero)
				return;

			UnhookWindowsHookEx(hookID);
			hookID = IntPtr.Zero;
		}

		/// <summary>
		/// Destructor. Unhook current hook
		/// </summary>
		~MouseHook() {
			Uninstall();
		}

		/// <summary>
		/// Sets hook and assigns its ID for tracking
		/// </summary>
		/// <param name="proc">Internal callback function</param>
		/// <returns>Hook ID</returns>
		private IntPtr SetHook(MouseHookHandler proc) {
			using (ProcessModule module = Process.GetCurrentProcess().MainModule)
				return SetWindowsHookEx(WH_MOUSE_LL, proc, GetModuleHandle(module.ModuleName), 0);
		}

		/// <summary>
		/// Callback function
		/// </summary>
		private IntPtr HookFunc(int nCode, IntPtr wParam, IntPtr lParam) {
			// parse system messages
			if (nCode >= 0) {
				if (MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
					if (LeftButtonDown != null)
						LeftButtonDown((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_LBUTTONUP == (MouseMessages)wParam)
					if (LeftButtonUp != null)
						LeftButtonUp((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_RBUTTONDOWN == (MouseMessages)wParam)
					if (RightButtonDown != null)
						RightButtonDown((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_RBUTTONUP == (MouseMessages)wParam)
					if (RightButtonUp != null)
						RightButtonUp((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_MOUSEMOVE == (MouseMessages)wParam)
					if (MouseMove != null)
						MouseMove((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_MOUSEWHEEL == (MouseMessages)wParam)
					if (MouseWheel != null)
						MouseWheel((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_LBUTTONDBLCLK == (MouseMessages)wParam)
					if (DoubleClick != null)
						DoubleClick((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_MBUTTONDOWN == (MouseMessages)wParam)
					if (MiddleButtonDown != null)
						MiddleButtonDown((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
				if (MouseMessages.WM_MBUTTONUP == (MouseMessages)wParam)
					if (MiddleButtonUp != null)
						MiddleButtonUp((MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT)));
			}
			return 1;
			//return CallNextHookEx(hookID, nCode, wParam, lParam);
		}

		#region WinAPI
		private const int WH_MOUSE_LL = 14;

		private enum MouseMessages {
			WM_LBUTTONDOWN = 0x0201,
			WM_LBUTTONUP = 0x0202,
			WM_MOUSEMOVE = 0x0200,
			WM_MOUSEWHEEL = 0x020A,
			WM_RBUTTONDOWN = 0x0204,
			WM_RBUTTONUP = 0x0205,
			WM_LBUTTONDBLCLK = 0x0203,
			WM_MBUTTONDOWN = 0x0207,
			WM_MBUTTONUP = 0x0208
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct POINT {
			public int x;
			public int y;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct MSLLHOOKSTRUCT {
			public POINT pt;
			public uint mouseData;
			public uint flags;
			public uint time;
			public IntPtr dwExtraInfo;
		}

		[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
		private static extern IntPtr SetWindowsHookEx(int idHook,
			MouseHookHandler lpfn, IntPtr hMod, uint dwThreadId);

		[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		public 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);
		#endregion
	}
}