昨天和两个同学一起玩魔兽3C的时候，由于很长时间我都是躲在练功房里砍木头人升级，而这种体力活不需要我监视英雄的举动，所以我就不断地切出游戏去上网，这种行为弄得两个哥们十分郁闷。呵呵，谁让我是主机呢，于是就不断地出现掉线的情况。
过后我就在想，那么如何在游戏中限制用户这种动作呢，使得他无法利用’ WIN功能键”不断地切进切出。
下面就是我给出的一个解决方案，原理是：利用一个底层的键盘钩子函数对待处理的键盘消息进行过滤。这个钩子即使在用户对窗口最小化或切换到另一个应用程序也是有效的。
// demo0.cpp : Defines the entry point for the application.
//******************************
//Author:phinecos
//Date:2008-4-17
//*******************************
#include "stdafx.h"
#include "demo0.h"
#define MAX_LOADSTRING 100
// Global Variables:
HINSTANCE hInst; // current instance
HWND hWnd = NULL; //窗口句柄
HHOOK g_hKeyboardHook;
TCHAR szTitle[MAX_LOADSTRING]; // The title bar text
TCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
BOOL isFullScreen = TRUE;//是否全屏
BOOL isActive=TRUE; // Window Active Flag Set To TRUE By Default
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK LowLevelKeyboardProc( int nCode, WPARAM wParam, LPARAM lParam )
{
if (nCode < 0 || nCode != HC_ACTION ) // do not process message
return CallNextHookEx( g_hKeyboardHook, nCode, wParam, lParam);
bool bEatKeystroke = false;
KBDLLHOOKSTRUCT* p = (KBDLLHOOKSTRUCT*)lParam;
switch (wParam)
{
case WM_KEYDOWN:
case WM_KEYUP:
{
bEatKeystroke = (isFullScreen && isActive && ((p->vkCode == VK_LWIN) || (p->vkCode == VK_RWIN)));
break;
}
}
if( bEatKeystroke )
return 1;
else
return CallNextHookEx( g_hKeyboardHook, nCode, wParam, lParam );
}
int APIENTRY _tWinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPTSTR lpCmdLine,
int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
MSG msg;
g_hKeyboardHook = SetWindowsHookEx( WH_KEYBOARD_LL, LowLevelKeyboardProc, GetModuleHandle(NULL), 0 ); //设置钩子
if (MessageBox(NULL,L"是否以全屏模式运行?", L"信息?",MB_YESNO|MB_ICONQUESTION)==IDNO)
{
isFullScreen = FALSE; // Windowed Mode
}
// Initialize global strings
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadString(hInstance, IDC_DEMO0, szWindowClass, MAX_LOADSTRING);
// Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}
// Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
UnhookWindowsHookEx( g_hKeyboardHook ); //卸载钩子
return (int) msg.wParam;
}
//
// FUNCTION: MyRegisterClass()
//
// PURPOSE: Registers the window class.
//
// COMMENTS:
//
// This function and its usage are only necessary if you want this code
// to be compatible with Win32 systems prior to the 'RegisterClassEx'
// function that was added to Windows 95. It is important to call this function
// so that the application will get 'well formed' small icons associated
// with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_DEMO0));
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = 0;
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassEx(&wcex);
}
VOID KillWindow(VOID) // Properly Kill The Window
{
if (isFullScreen) // Are We In Fullscreen Mode?
{
ChangeDisplaySettings(NULL,0); // If So Switch Back To The Desktop
ShowCursor(TRUE); // Show Mouse Pointer
}
if (hWnd && !DestroyWindow(hWnd)) // Are We Able To Destroy The Window?
{
MessageBox(NULL,L"Could Not Release hWnd.",L"SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
hWnd=NULL; // Set hWnd To NULL
}
if (!UnregisterClass(szWindowClass,hInst)) // Are We Able To Unregister Class
{
MessageBox(NULL,L"Could Not Unregister Class.",L"SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
hInst=NULL; // Set hInstance To NULL
}
}
BOOL MyCreateWindow(TCHAR* title, int width, int height, int bits, BOOL fullscreenflag)
{
DWORD dwExStyle; // Window Extended Style
DWORD dwStyle; // Window Style
RECT WindowRect; // Grabs Rectangle Upper Left / Lower Right Values
WindowRect.left=(long)0; // Set Left Value To 0
WindowRect.right=(long)width; // Set Right Value To Requested Width
WindowRect.top=(long)0; // Set Top Value To 0
WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height
isFullScreen = fullscreenflag; // Set The Global Fullscreen Flag
if (isFullScreen) // Attempt Fullscreen Mode?
{
DEVMODE dmScreenSettings; // Device Mode
memset(&dmScreenSettings,0,sizeof(dmScreenSettings)); // Makes Sure Memory's Cleared
dmScreenSettings.dmSize=sizeof(dmScreenSettings); // Size Of The Devmode Structure
dmScreenSettings.dmPelsWidth = width; // Selected Screen Width
dmScreenSettings.dmPelsHeight = height; // Selected Screen Height
dmScreenSettings.dmBitsPerPel = bits; // Selected Bits Per Pixel
dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
// Try To Set Selected Mode And Get Results. NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.
if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)
{
// If The Mode Fails, Offer Two Options. Quit Or Use Windowed Mode.
if (MessageBox(NULL,L"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?",L"Infomation",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)
{
isFullScreen = FALSE; // Windowed Mode Selected. Fullscreen = FALSE
}
else
{
// Pop Up A Message Box Letting User Know The Program Is Closing.
MessageBox(NULL,L"Program Will Now Close.",L"ERROR",MB_OK|MB_ICONSTOP);
return FALSE; // Return FALSE
}
}
}
if (isFullScreen) // Are We Still In Fullscreen Mode?
{
dwExStyle=WS_EX_APPWINDOW; // Window Extended Style
dwStyle=WS_POPUP; // Windows Style
ShowCursor(FALSE); // Hide Mouse Pointer
}
else
{
dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window Extended Style
dwStyle=WS_OVERLAPPEDWINDOW; // Windows Style
}
AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle); // Adjust Window To True Requested Size
// Create The Window
if (!(hWnd=CreateWindowEx( dwExStyle, // Extended Style For The Window
szWindowClass, // Class Name
title, // Window Title
dwStyle | // Defined Window Style
WS_CLIPSIBLINGS | // Required Window Style
WS_CLIPCHILDREN, // Required Window Style
0, 0, // Window Position
WindowRect.right-WindowRect.left, // Calculate Window Width
WindowRect.bottom-WindowRect.top, // Calculate Window Height
NULL, // No Parent Window
NULL, // No Menu
hInst, // Instance
NULL))) // Dont Pass Anything To WM_CREATE
{
KillWindow(); // Reset The Display
MessageBox(NULL,L"Window Creation Error.",L"ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
ShowWindow(hWnd,SW_SHOW); // Show The Window
SetForegroundWindow(hWnd); // Slightly Higher Priority
SetFocus(hWnd); // Sets Keyboard Focus To The Window
return TRUE; // Success
}
//
// FUNCTION: InitInstance(HINSTANCE, int)
//
// PURPOSE: Saves instance handle and creates main window
//
// COMMENTS:
//
// In this function, we save the instance handle in a global variable and
// create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
MyRegisterClass(hInstance);
hInst = hInstance; // Store instance handle in our global variable
MyCreateWindow(szTitle,640,480,16,isFullScreen);
if (!hWnd)
{
return FALSE;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
return TRUE;
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
PAINTSTRUCT ps;
HDC hdc;
switch (message)
{
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_ACTIVATEAPP:
// g_bWindowActive is used to control if the Windows key is filtered by the keyboard hook or not.
if( wParam == TRUE )
isActive = TRUE;
else
isActive = FALSE;
break;
case WM_KEYDOWN:
{
if (wParam==VK_ESCAPE)
{//退出
KillWindow(); // Kill Our Current Window
}
}
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
参考资料：
1， Disabling Shortcut Keys in Games
2， Nehe OpenGL tutorial
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2008/04/17/1157739.html，如需转载请自行联系原作者
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