sdk/samples/all in on code/Visual Studio 2008/CppHookDll/HookDll.cpp

   1 /****************************** Module Header ******************************\
   2 * Module Name:  HookDll.cpp
   3 * Project:              CppHookDll
   4 * Copyright (c) Microsoft Corporation.
   5 *
   6 * Defines the exported hook procedure.
   7 *
   8 * This source is subject to the Microsoft Public License.
   9 * See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  10 * All other rights reserved.
  11 *
  12 * History:
  13 * * 5/01/2009 11:04 PM RongChun Zhang Created
  14 \***************************************************************************/
  15
  16
  17 #include <windows.h>
  18
  19 #define HOOKDLL_EXPORTS
  20 #include "HookDll.h"
  21
  22
  23 // Shared data among all instances.
  24 #pragma data_seg(".HOOKDATA")
  25 HWND g_hWnd = NULL;             // Window handle
  26 HHOOK g_hHook = NULL;           // Hook handle
  27
  28 // Get module from address
  29 HMODULE WINAPI ModuleFromAddress(PVOID pv)
  30 {
  31         MEMORY_BASIC_INFORMATION mbi;
  32         if (::VirtualQuery(pv, &mbi, sizeof(mbi)) != 0)
  33         {
  34                 return (HMODULE)mbi.AllocationBase;
  35         }
  36         else
  37         {
  38                 return NULL;
  39         }
  40 }
  41
  42 // Hook callback
  43 LRESULT CALLBACK KeyboardHookProc(int nCode, WPARAM wParam, LPARAM lParam)
  44 {
  45     if (nCode < 0 || nCode == HC_NOREMOVE)
  46                 return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
  47
  48     if (lParam & 0x40000000)    // Check the previous key state
  49         {
  50                 return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
  51         }
  52
  53         // Post private messages to Main window
  54         // wParam specifies the virtual key code
  55         // lParam specifies the key data
  56     ::PostMessage(g_hWnd, WM_KEYSTROKE, wParam, lParam);
  57
  58     return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
  59 }
  60
  61 // Install or uninstall the hook
  62 BOOL WINAPI SetKeyboardHook(BOOL bInstall, DWORD dwThreadId, HWND hWndCaller)
  63 {
  64         BOOL bOk;
  65         g_hWnd = hWndCaller;
  66
  67         if (bInstall)
  68         {
  69                 g_hHook = ::SetWindowsHookEx(WH_KEYBOARD, KeyboardHookProc,
  70                         ModuleFromAddress(KeyboardHookProc), dwThreadId);
  71                 bOk = (g_hHook != NULL);
  72         }
  73         else
  74         {
  75                 bOk = ::UnhookWindowsHookEx(g_hHook);
  76                 g_hHook = NULL;
  77         }
  78
  79         return bOk;
  80 }
  81
  82
  83 // Hook callback
  84 LRESULT CALLBACK LowKeyboardHookProc(int nCode, WPARAM wParam, LPARAM lParam)
  85 {
  86     if (nCode < 0 || nCode == HC_NOREMOVE)
  87                 return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
  88
  89     if (lParam & 0x40000000)    // Check the previous key state
  90         {
  91                 return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
  92         }
  93
  94         KBDLLHOOKSTRUCT  *pkbhs = (KBDLLHOOKSTRUCT *)lParam;
  95
  96         //check that the message is from keyboard or is synthesized by SendInput API
  97         if((pkbhs->flags & LLKHF_INJECTED))
  98         return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
  99
 100         if(wParam == WM_KEYDOWN)
 101         {
 102                 // Post private messages to Main window
 103                 // wParam specifies the virtual key code
 104                 // lParam specifies the scan code
 105                 ::PostMessage(g_hWnd, WM_KEYINPUT, pkbhs->vkCode, pkbhs->scanCode);
 106         }
 107
 108     return ::CallNextHookEx(g_hHook, nCode, wParam, lParam);
 109 }
 110
 111 BOOL WINAPI SetLowKeyboardHook(BOOL bInstall, DWORD dwThreadId, HWND hWndCaller)
 112 {
 113         BOOL bOk;
 114         g_hWnd = hWndCaller;
 115
 116         if (bInstall)
 117         {
 118                 g_hHook = ::SetWindowsHookEx(WH_KEYBOARD_LL, LowKeyboardHookProc,
 119                         ModuleFromAddress(LowKeyboardHookProc), dwThreadId);
 120                 bOk = (g_hHook != NULL);
 121         }
 122         else
 123         {
 124                 bOk = ::UnhookWindowsHookEx(g_hHook);
 125                 g_hHook = NULL;
 126         }
 127
 128         return bOk;
 129 }