C#键盘鼠标钩子实例
本文实例讲述了C#键盘鼠标钩子的实现方法。分享给大家供大家参考。具体实现方法如下：
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows.Forms; using System.Runtime.InteropServices; using System.ComponentModel; using System.Reflection;namespace Alif.CommonAPI.WindowsAPI { /// <summary> /// 用户键盘鼠标钩子 /// </summary> public class UserActivityHook { #region Windows structure definitions
/// <summary> /// The POINT structure defines the x- and y- coordinates of a point. /// </summary> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/rectangl_0tiq.asp /// </remarks> [StructLayout(LayoutKind.Sequential)] private class POINT { /// <summary> /// Specifies the x-coordinate of the point. /// </summary> public int x; /// <summary> /// Specifies the y-coordinate of the point. /// </summary> public int y; }
/// <summary> /// The MOUSEHOOKSTRUCT structure contains information about a mouse event passed to a WH_MOUSE hook procedure, MouseProc. /// </summary> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks/hookreference/hookstructures/cwpstruct.asp /// </remarks> [StructLayout(LayoutKind.Sequential)] private class MouseHookStruct { /// <summary> /// Specifies a POINT structure that contains the x- and y-coordinates of the cursor, in screen coordinates. /// </summary> public POINT pt; /// <summary> /// Handle to the window that will receive the mouse message corresponding to the mouse event. /// </summary> public int hwnd; /// <summary> /// Specifies the hit-test value. For a list of hit-test values, see the description of the WM_NCHITTEST message. /// </summary> public int wHitTestCode; /// <summary> /// Specifies extra information associated with the message. /// </summary> public int dwExtraInfo; }
/// <summary> /// The MSLLHOOKSTRUCT structure contains information about a low-level keyboard input event. /// </summary> [StructLayout(LayoutKind.Sequential)] private class MouseLLHookStruct { /// <summary> /// Specifies a POINT structure that contains the x- and y-coordinates of the cursor, in screen coordinates. /// </summary> public POINT pt; /// <summary> /// If the message is WM_MOUSEWHEEL, the high-order word of this member is the wheel delta. /// The low-order word is reserved. A positive value indicates that the wheel was rotated forward, /// away from the user; a negative value indicates that the wheel was rotated backward, toward the user. /// One wheel click is defined as WHEEL_DELTA, which is 120. ///If the message is WM_XBUTTONDOWN, WM_XBUTTONUP, WM_XBUTTONDBLCLK, WM_NCXBUTTONDOWN, WM_NCXBUTTONUP, /// or WM_NCXBUTTONDBLCLK, the high-order word specifies which X button was pressed or released, /// and the low-order word is reserved. This value can be one or more of the following values. Otherwise, mouseData is not used. ///XBUTTON1 ///The first X button was pressed or released. ///XBUTTON2 ///The second X button was pressed or released. /// </summary> public int mouseData; /// <summary> /// Specifies the event-injected flag. An application can use the following value to test the mouse flags. Value Purpose ///LLMHF_INJECTED Test the event-injected flag. ///0 ///Specifies whether the event was injected. The value is 1 if the event was injected; otherwise, it is 0. ///1-15 ///Reserved. /// </summary> public int flags; /// <summary> /// Specifies the time stamp for this message. /// </summary> public int time; /// <summary> /// Specifies extra information associated with the message. /// </summary> public int dwExtraInfo; }
/// <summary> /// The KBDLLHOOKSTRUCT structure contains information about a low-level keyboard input event. /// </summary> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks/hookreference/hookstructures/cwpstruct.asp /// </remarks> [StructLayout(LayoutKind.Sequential)] private class KeyboardHookStruct { /// <summary> /// Specifies a virtual-key code. The code must be a value in the range 1 to 254. /// </summary> public int vkCode; /// <summary> /// Specifies a hardware scan code for the key. /// </summary> public int scanCode; /// <summary> /// Specifies the extended-key flag, event-injected flag, context code, and transition-state flag. /// </summary> public int flags; /// <summary> /// Specifies the time stamp for this message. /// </summary> public int time; /// <summary> /// Specifies extra information associated with the message. /// </summary> public int dwExtraInfo; } #endregion
#region Windows function imports /// <summary> /// The SetWindowsHookEx function installs an application-defined hook procedure into a hook chain. /// You would install a hook procedure to monitor the system for certain types of events. These events /// are associated either with a specific thread or with all threads in the same desktop as the calling thread. /// </summary> /// <param name="idHook"> /// [in] Specifies the type of hook procedure to be installed. This parameter can be one of the following values. /// </param> /// <param name="lpfn"> /// [in] Pointer to the hook procedure. If the dwThreadId parameter is zero or specifies the identifier of a /// thread created by a different process, the lpfn parameter must point to a hook procedure in a dynamic-link /// library (DLL). Otherwise, lpfn can point to a hook procedure in the code associated with the current process. /// </param> /// <param name="hMod"> /// [in] Handle to the DLL containing the hook procedure pointed to by the lpfn parameter. /// The hMod parameter must be set to NULL if the dwThreadId parameter specifies a thread created by /// the current process and if the hook procedure is within the code associated with the current process. /// </param> /// <param name="dwThreadId"> /// [in] Specifies the identifier of the thread with which the hook procedure is to be associated. /// If this parameter is zero, the hook procedure is associated with all existing threads running in the /// same desktop as the calling thread. /// </param> /// <returns> /// If the function succeeds, the return value is the handle to the hook procedure. /// If the function fails, the return value is NULL. To get extended error information, call GetLastError. /// </returns> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks/hookreference/hookfunctions/setwindowshookex.asp /// </remarks> [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall, SetLastError = true)] private static extern int SetWindowsHookEx( int idHook, HookProc lpfn, IntPtr hMod, int dwThreadId);
/// <summary> /// The UnhookWindowsHookEx function removes a hook procedure installed in a hook chain by the SetWindowsHookEx function. /// </summary> /// <param name="idHook"> /// [in] Handle to the hook to be removed. This parameter is a hook handle obtained by a previous call to SetWindowsHookEx. /// </param> /// <returns> /// If the function succeeds, the return value is nonzero. /// If the function fails, the return value is zero. To get extended error information, call GetLastError. /// </returns> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks/hookreference/hookfunctions/setwindowshookex.asp /// </remarks> [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall, SetLastError = true)] private static extern int UnhookWindowsHookEx(int idHook);
/// <summary> /// The CallNextHookEx function passes the hook information to the next hook procedure in the current hook chain. /// A hook procedure can call this function either before or after processing the hook information. /// </summary> /// <param name="idHook">Ignored.</param> /// <param name="nCode"> /// [in] Specifies the hook code passed to the current hook procedure. /// The next hook procedure uses this code to determine how to process the hook information. /// </param> /// <param name="wParam"> /// [in] Specifies the wParam value passed to the current hook procedure. /// The meaning of this parameter depends on the type of hook associated with the current hook chain. /// </param> /// <param name="lParam"> /// [in] Specifies the lParam value passed to the current hook procedure. /// The meaning of this parameter depends on the type of hook associated with the current hook chain. /// </param> /// <returns> /// This value is returned by the next hook procedure in the chain. /// The current hook procedure must also return this value. The meaning of the return value depends on the hook type. /// For more information, see the descriptions of the individual hook procedures. /// </returns> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks/hookreference/hookfunctions/setwindowshookex.asp /// </remarks> [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)] private static extern int CallNextHookEx( int idHook, int nCode, int wParam, IntPtr lParam);
/// <summary> /// The CallWndProc hook procedure is an application-defined or library-defined callback /// function used with the SetWindowsHookEx function. The HOOKPROC type defines a pointer /// to this callback function. CallWndProc is a placeholder for the application-defined /// or library-defined function name. /// </summary> /// <param name="nCode"> /// [in] Specifies whether the hook procedure must process the message. /// If nCode is HC_ACTION, the hook procedure must process the message. /// If nCode is less than zero, the hook procedure must pass the message to the /// CallNextHookEx function without further processing and must return the /// value returned by CallNextHookEx. /// </param> /// <param name="wParam"> /// [in] Specifies whether the message was sent by the current thread. /// If the message was sent by the current thread, it is nonzero; otherwise, it is zero. /// </param> /// <param name="lParam"> /// [in] Pointer to a CWPSTRUCT structure that contains details about the message. /// </param> /// <returns> /// If nCode is less than zero, the hook procedure must return the value returned by CallNextHookEx. /// If nCode is greater than or equal to zero, it is highly recommended that you call CallNextHookEx /// and return the value it returns; otherwise, other applications that have installed WH_CALLWNDPROC /// hooks will not receive hook notifications and may behave incorrectly as a result. If the hook /// procedure does not call CallNextHookEx, the return value should be zero. /// </returns> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks/hookreference/hookfunctions/callwndproc.asp /// </remarks> private delegate int HookProc(int nCode, int wParam, IntPtr lParam);
/// <summary> /// The ToAscii function translates the specified virtual-key code and keyboard /// state to the corresponding character or characters. The function translates the code /// using the input language and physical keyboard layout identified by the keyboard layout handle. /// </summary> /// <param name="uVirtKey"> /// [in] Specifies the virtual-key code to be translated. /// </param> /// <param name="uScanCode"> /// [in] Specifies the hardware scan code of the key to be translated. /// The high-order bit of this value is set if the key is up (not pressed). /// </param> /// <param name="lpbKeyState"> /// [in] Pointer to a 256-byte array that contains the current keyboard state. /// Each element (byte) in the array contains the state of one key. /// If the high-order bit of a byte is set, the key is down (pressed). /// The low bit, if set, indicates that the key is toggled on. In this function, /// only the toggle bit of the CAPS LOCK key is relevant. The toggle state /// of the NUM LOCK and SCROLL LOCK keys is ignored. /// </param> /// <param name="lpwTransKey"> /// [out] Pointer to the buffer that receives the translated character or characters. /// </param> /// <param name="fuState"> /// [in] Specifies whether a menu is active. This parameter must be 1 if a menu is active, or 0 otherwise. /// </param> /// <returns> /// If the specified key is a dead key, the return value is negative. Otherwise, it is one of the following values. /// Value Meaning /// 0 The specified virtual key has no translation for the current state of the keyboard. /// 1 One character was copied to the buffer. /// 2 Two characters were copied to the buffer. This usually happens when a dead-key character /// (accent or diacritic) stored in the keyboard layout cannot be composed with the specified /// virtual key to form a single character. /// </returns> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/userinput/keyboardinput/keyboardinputreference/keyboardinputfunctions/toascii.asp /// </remarks> [DllImport("user32")] private static extern int ToAscii( int uVirtKey, int uScanCode, byte[] lpbKeyState, byte[] lpwTransKey, int fuState);
/// <summary> /// The GetKeyboardState function copies the status of the 256 virtual keys to the /// specified buffer. /// </summary> /// <param name="pbKeyState"> /// [in] Pointer to a 256-byte array that contains keyboard key states. /// </param> /// <returns> /// If the function succeeds, the return value is nonzero. /// If the function fails, the return value is zero. To get extended error information, call GetLastError. /// </returns> /// <remarks> /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/userinput/keyboardinput/keyboardinputreference/keyboardinputfunctions/toascii.asp /// </remarks> [DllImport("user32")] private static extern int GetKeyboardState(byte[] pbKeyState);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)] private static extern short GetKeyState(int vKey);
#endregion
#region Windows constants
//values from Winuser.h in Microsoft SDK. /// <summary> /// Windows NT/2000/XP: Installs a hook procedure that monitors low-level mouse input events. /// </summary> private const int WH_MOUSE_LL = 14; /// <summary> /// Windows NT/2000/XP: Installs a hook procedure that monitors low-level keyboard input events. /// </summary> private const int WH_KEYBOARD_LL = 13;
/// <summary> /// Installs a hook procedure that monitors mouse messages. For more information, see the MouseProc hook procedure. /// </summary> private const int WH_MOUSE = 7; /// <summary> /// Installs a hook procedure that monitors keystroke messages. For more information, see the KeyboardProc hook procedure. /// </summary> private const int WH_KEYBOARD = 2;
/// <summary> /// The WM_MOUSEMOVE message is posted to a window when the cursor moves. /// </summary> private const int WM_MOUSEMOVE = 0x200; /// <summary> /// The WM_LBUTTONDOWN message is posted when the user presses the left mouse button /// </summary> private const int WM_LBUTTONDOWN = 0x201; /// <summary> /// The WM_RBUTTONDOWN message is posted when the user presses the right mouse button /// </summary> private const int WM_RBUTTONDOWN = 0x204; /// <summary> /// The WM_MBUTTONDOWN message is posted when the user presses the middle mouse button /// </summary> private const int WM_MBUTTONDOWN = 0x207; /// <summary> /// The WM_LBUTTONUP message is posted when the user releases the left mouse button /// </summary> private const int WM_LBUTTONUP = 0x202; /// <summary> /// The WM_RBUTTONUP message is posted when the user releases the right mouse button /// </summary> private const int WM_RBUTTONUP = 0x205; /// <summary> /// The WM_MBUTTONUP message is posted when the user releases the middle mouse button /// </summary> private const int WM_MBUTTONUP = 0x208; /// <summary> /// The WM_LBUTTONDBLCLK message is posted when the user double-clicks the left mouse button /// </summary> private const int WM_LBUTTONDBLCLK = 0x203; /// <summary> /// The WM_RBUTTONDBLCLK message is posted when the user double-clicks the right mouse button /// </summary> private const int WM_RBUTTONDBLCLK = 0x206; /// <summary> /// The WM_RBUTTONDOWN message is posted when the user presses the right mouse button /// </summary> private const int WM_MBUTTONDBLCLK = 0x209; /// <summary> /// The WM_MOUSEWHEEL message is posted when the user presses the mouse wheel. /// </summary> private const int WM_MOUSEWHEEL = 0x020A;
/// <summary> /// The WM_KEYDOWN message is posted to the window with the keyboard focus when a nonsystem /// key is pressed. A nonsystem key is a key that is pressed when the ALT key is not pressed. /// </summary> private const int WM_KEYDOWN = 0x100; /// <summary> /// The WM_KEYUP message is posted to the window with the keyboard focus when a nonsystem /// key is released. A nonsystem key is a key that is pressed when the ALT key is not pressed, /// or a keyboard key that is pressed when a window has the keyboard focus. /// </summary> private const int WM_KEYUP = 0x101; /// <summary> /// The WM_SYSKEYDOWN message is posted to the window with the keyboard focus when the user /// presses the F10 key (which activates the menu bar) or holds down the ALT key and then /// presses another key. It also occurs when no window currently has the keyboard focus; /// in this case, the WM_SYSKEYDOWN message is sent to the active window. The window that /// receives the message can distinguish between these two contexts by checking the context /// code in the lParam parameter. /// </summary> private const int WM_SYSKEYDOWN = 0x104; /// <summary> /// The WM_SYSKEYUP message is posted to the window with the keyboard focus when the user /// releases a key that was pressed while the ALT key was held down. It also occurs when no /// window currently has the keyboard focus; in this case, the WM_SYSKEYUP message is sent /// to the active window. The window that receives the message can distinguish between /// these two contexts by checking the context code in the lParam parameter. /// </summary> private const int WM_SYSKEYUP = 0x105;
private const byte VK_SHIFT = 0x10; private const byte VK_CAPITAL = 0x14; private const byte VK_NUMLOCK = 0x90;
#endregion
/// <summary> /// Creates an instance of UserActivityHook object and sets mouse and keyboard hooks. /// </summary> /// <exception cref="Win32Exception">Any windows problem.</exception> public UserActivityHook() { Start(); }
/// <summary> /// Creates an instance of UserActivityHook object and installs both or one of mouse and/or keyboard hooks and starts rasing events /// </summary> /// <param name="InstallMouseHook"><b>true</b> if mouse events must be monitored</param> /// <param name="InstallKeyboardHook"><b>true</b> if keyboard events must be monitored</param> /// <exception cref="Win32Exception">Any windows problem.</exception> /// <remarks> /// To create an instance without installing hooks call new UserActivityHook(false, false) /// </remarks> public UserActivityHook(bool InstallMouseHook, bool InstallKeyboardHook) { Start(InstallMouseHook, InstallKeyboardHook); }
/// <summary> /// Destruction. /// </summary> ~UserActivityHook() { //uninstall hooks and do not throw exceptions Stop(true, true, false); }
/// <summary> /// Occurs when the user moves the mouse, presses any mouse button or scrolls the wheel /// </summary> public event MouseEventHandler OnMouseActivity; /// <summary> /// Occurs when the user presses a key /// </summary> public event KeyEventHandler KeyDown; /// <summary> /// Occurs when the user presses and releases /// </summary> public event KeyPressEventHandler KeyPress; /// <summary> /// Occurs when the user releases a key /// </summary> public event KeyEventHandler KeyUp;
/// <summary> /// Stores the handle to the mouse hook procedure. /// </summary> private int hMouseHook = 0; /// <summary> /// Stores the handle to the keyboard hook procedure. /// </summary> private int hKeyboardHook = 0;
/// <summary> /// Declare MouseHookProcedure as HookProc type. /// </summary> private static HookProc MouseHookProcedure; /// <summary> /// Declare KeyboardHookProcedure as HookProc type. /// </summary> private static HookProc KeyboardHookProcedure;
/// <summary> /// Installs both mouse and keyboard hooks and starts raising events /// </summary> /// <exception cref="Win32Exception">Any windows problem.</exception> public void Start() { this.Start(true, true); }
/// <summary> /// Installs both or one of mouse and/or keyboard hooks and starts raising events /// </summary> /// <param name="InstallMouseHook"><b>true</b> if mouse events must be monitored</param> /// <param name="InstallKeyboardHook"><b>true</b> if keyboard events must be monitored</param> /// <exception cref="Win32Exception">Any windows problem.</exception> public void Start(bool InstallMouseHook, bool InstallKeyboardHook) { // install Mouse hook only if it is not installed and must be installed if (hMouseHook == 0 && InstallMouseHook) { // Create an instance of HookProc. MouseHookProcedure = new HookProc(MouseHookProc); //install hook hMouseHook = SetWindowsHookEx( WH_MOUSE_LL, MouseHookProcedure, Marshal.GetHINSTANCE( Assembly.GetExecutingAssembly().GetModules()[0]), 0); //If SetWindowsHookEx fails. if (hMouseHook == 0) { //Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set. int errorCode = Marshal.GetLastWin32Error(); //do cleanup Stop(true, false, false); //Initializes and throws a new instance of the Win32Exception class with the specified error. throw new Win32Exception(errorCode); } }
// install Keyboard hook only if it is not installed and must be installed if (hKeyboardHook == 0 && InstallKeyboardHook) { // Create an instance of HookProc. KeyboardHookProcedure = new HookProc(KeyboardHookProc); //install hook hKeyboardHook = SetWindowsHookEx( WH_KEYBOARD_LL, KeyboardHookProcedure, Marshal.GetHINSTANCE( Assembly.GetExecutingAssembly().GetModules()[0]), 0); //If SetWindowsHookEx fails. if (hKeyboardHook == 0) { //Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set. int errorCode = Marshal.GetLastWin32Error(); //do cleanup Stop(false, true, false); //Initializes and throws a new instance of the Win32Exception class with the specified error. throw new Win32Exception(errorCode); } } }
/// <summary> /// Stops monitoring both mouse and keyboard events and rasing events. /// </summary> /// <exception cref="Win32Exception">Any windows problem.</exception> public void Stop() { this.Stop(true, true, true); }
/// <summary> /// Stops monitoring both or one of mouse and/or keyboard events and rasing events. /// </summary> /// <param name="UninstallMouseHook"><b>true</b> if mouse hook must be uninstalled</param> /// <param name="UninstallKeyboardHook"><b>true</b> if keyboard hook must be uninstalled</param> /// <param name="ThrowExceptions"><b>true</b> if exceptions which occured during uninstalling must be thrown</param> /// <exception cref="Win32Exception">Any windows problem.</exception> public void Stop(bool UninstallMouseHook, bool UninstallKeyboardHook, bool ThrowExceptions) { //if mouse hook set and must be uninstalled if (hMouseHook != 0 && UninstallMouseHook) { //uninstall hook int retMouse = UnhookWindowsHookEx(hMouseHook); //reset invalid handle hMouseHook = 0; //if failed and exception must be thrown if (retMouse == 0 && ThrowExceptions) { //Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set. int errorCode = Marshal.GetLastWin32Error(); //Initializes and throws a new instance of the Win32Exception class with the specified error. throw new Win32Exception(errorCode); } }
//if keyboard hook set and must be uninstalled if (hKeyboardHook != 0 && UninstallKeyboardHook) { //uninstall hook int retKeyboard = UnhookWindowsHookEx(hKeyboardHook); //reset invalid handle hKeyboardHook = 0; //if failed and exception must be thrown if (retKeyboard == 0 && ThrowExceptions) { //Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set. int errorCode = Marshal.GetLastWin32Error(); //Initializes and throws a new instance of the Win32Exception class with the specified error. throw new Win32Exception(errorCode); } } }
/// <summary> /// A callback function which will be called every time a mouse activity detected. /// </summary> /// <param name="nCode"> /// [in] Specifies whether the hook procedure must process the message. /// If nCode is HC_ACTION, the hook procedure must process the message. /// If nCode is less than zero, the hook procedure must pass the message to the /// CallNextHookEx function without further processing and must return the /// value returned by CallNextHookEx. /// </param> /// <param name="wParam"> /// [in] Specifies whether the message was sent by the current thread. /// If the message was sent by the current thread, it is nonzero; otherwise, it is zero. /// </param> /// <param name="lParam"> /// [in] Pointer to a CWPSTRUCT structure that contains details about the message. /// </param> /// <returns> /// If nCode is less than zero, the hook procedure must return the value returned by CallNextHookEx. /// If nCode is greater than or equal to zero, it is highly recommended that you call CallNextHookEx /// and return the value it returns; otherwise, other applications that have installed WH_CALLWNDPROC /// hooks will not receive hook notifications and may behave incorrectly as a result. If the hook /// procedure does not call CallNextHookEx, the return value should be zero. /// </returns> private int MouseHookProc(int nCode, int wParam, IntPtr lParam) { // if ok and someone listens to our events if ((nCode >= 0) && (OnMouseActivity != null)) { //Marshall the data from callback. MouseLLHookStruct mouseHookStruct = (MouseLLHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseLLHookStruct));
//detect button clicked MouseButtons button = MouseButtons.None; short mouseDelta = 0; switch (wParam) { case WM_LBUTTONDOWN: //case WM_LBUTTONUP: //case WM_LBUTTONDBLCLK: button = MouseButtons.Left; break; case WM_RBUTTONDOWN: //case WM_RBUTTONUP: //case WM_RBUTTONDBLCLK: button = MouseButtons.Right; break; case WM_MOUSEWHEEL: //If the message is WM_MOUSEWHEEL, the high-order word of mouseData member is the wheel delta. //One wheel click is defined as WHEEL_DELTA, which is 120. //(value >> 16) & 0xffff; retrieves the high-order word from the given 32-bit value &
