在Windows操作系统中.docx

1、在Windows操作系统中在Windows操作系统中，当用户按下PrintScreen按钮后，Windows自动将当前屏幕的图像拷贝到系统剪贴板中，这时可以通过画笔这个小程序将剪贴板中的内容保存成图像文件，可以看出，如果需要将当前屏幕保存下来还是比较麻烦的，能否可以自己编写一个应用程序，自动将当前屏幕的内容保存到一个图像文件中去呢？这个答案是肯定的，本实例应用程序就是利用通用的热键管理DLL库实现的热键功能，在收到热键通知后截取屏幕的内容并保存到bmp文件中。例如我们设置图片保存路径为c：，热键为F9 + Control，然后按Change按钮设置好热键，那么当我们按下CTRL+F9后，当前界

2、面将以BMP图像文件的格式被保存在C：目录下。一、实现方法热键管理DLL实际上是一个键盘钩子，由它来监视系统的键盘事件。如果有和程序登记符合的按键组合就通知该程序的窗口。为了应用方便，本实例把它做成了一个标准的管理库来为其它的程序通过热键服务，它有两个输出函数：AddHotkey（）和DeleteHotkey（），程序只需要调用这两个函数就可以了，如果编译之后不用改变热键，则只需要AddHotkey就可以了。DLL中的所有的全局变量都放在一个共享段中，定义如下：#pragma data_seg(shareddata)HHOOK hHook =NULL; /钩子句柄UINT nHookCount

3、 =0; /挂接的程序数目static UCHAR HotKeyMAX_KEY = 0; /热键虚拟键码static UCHAR HotKeyMaskMAX_KEY = 0; /组合掩码, control=4,alt=2,shift=1static HWND hCallWndMAX_KEY = 0; /window handle associated with hotkeystatic int KeyCount =0;static UCHAR MaskBits =0; /00000 Ctrl=4 & Alt=2 & Shift=1#pragma data_seg() 关于共享段，有几点重要的说

4、明：一是必须在链接选项里指定该段为共享：一种方法是在project-settings-link-object/library中加上/section:shareddata,rws；第二种方法是在def文件的sections里加上一句shareddata read write shared；第三种指定共享段的方法在程序里加上一句#pragma comment(linker,section:shareddata,rws)。二是所有的变量必须初始化，否则链接程序会把它放到普通数据段。三是如果不初始化变量，需要在段外用_declspec(allocate(shareddata) 变量类型 变量名的方式定

5、义。DLL中的两个输出函数分别用来添加/删除热键，函数代码如下：BOOL _declspec(dllexport) _stdcall AddHotkey(HWND hWnd,UCHAR cKey,UCHAR cMask) BOOL bAdded=FALSE;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=0)hCallWndindex=hWnd;HotKeyindex=cKey;HotKeyMaskindex=cMask;bAdded=TRUE;KeyCount+;break;return bAdded;/删除热键BOOL _decls

6、pec(dllexport) _stdcall DeleteHotkey(HWND hWnd,UCHAR cKey,UCHAR cMask) BOOL bRemoved=FALSE;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=hWnd)if(HotKeyindex=cKey&HotKeyMaskindex=cMask)hCallWndindex=NULL;HotKeyindex=0;HotKeyMaskindex=0;bRemoved=TRUE;KeyCount-;break;return bRemoved; DLL中的钩子函数如下

7、：LRESULT CALLBACK KeyboardProc(int nCode,WPARAM wParam,LPARAM lParam) BOOL bProcessed=FALSE;if(HC_ACTION=nCode)if(lParam&0xc0000000)=0xc0000000)/ 有键松开switch(wParam)case VK_MENU:MaskBits&=ALTBIT;break;case VK_CONTROL:MaskBits&=CTRLBIT;break;case VK_SHIFT:MaskBits&=SHIFTBIT;break;default: /judge the k

8、ey and send messagebreak;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=NULL)continue; if(IsWindow(hCallWndindex)&(HotKeyindex=wParam)&(HotKeyMaskindex=MaskBits)SendMessage(hCallWndindex,WM_HOTKEY,wParam,WM_KEYUP);bProcessed=TRUE;else if(lParam&0xc000ffff)=1) /有键按下switch(wParam)case VK_MENU:Ma

9、skBits|=ALTBIT;break;case VK_CONTROL:MaskBits|=CTRLBIT;break;case VK_SHIFT:MaskBits|=SHIFTBIT;break;default: /judge the key and send messagebreak;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=NULL)continue;if(IsWindow(hCallWndindex)&(HotKeyindex=wParam)&(HotKeyMaskindex=MaskBits)SendMessage(h

10、CallWndindex,WM_HOTKEY,wParam,WM_KEYDOWN);bProcessed=TRUE;if(!bProcessed) /一般按键事件，为监视键盘的程序留出余地for(int index=0;index 1000#pragma once#endif / _MSC_VER 1000#ifndef _AFXWIN_H_#error include stdafx.h before including this file for PCH#endif#include resource.h / main symbols class CHookApp : public CWinA

11、pppublic:CHookApp();/ Overrides/ ClassWizard generated virtual function overrides/AFX_VIRTUAL(CHookApp)public:virtual BOOL InitInstance();virtual int ExitInstance();/AFX_VIRTUAL/AFX_MSG(CHookApp)/ NOTE - the ClassWizard will add and remove member functions here./ DO NOT EDIT what you see in these bl

12、ocks of generated code !/AFX_MSGDECLARE_MESSAGE_MAP();LRESULT CALLBACK KeyboardProc(int nCode,WPARAM wParam, LPARAM lParam);BOOL _declspec(dllexport)_stdcall AddHotkey(HWND,UCHAR key,UCHAR mask);BOOL _declspec(dllexport)_stdcall DeleteHotkey(HWND,UCHAR key,UCHAR mask);BOOL InitHotkey();BOOL UnInit()

13、;#endif / Hook.cpp : Defines the initialization routines for the DLL.#include stdafx.h#include hook.h#include #ifdef _DEBUG#define new DEBUG_NEW#undef THIS_FILEstatic char THIS_FILE = _FILE_;#endif#define MAX_KEY 100#define CTRLBIT 0x04#define ALTBIT 0x02#define SHIFTBIT 0x01 #pragma data_seg(shared

14、data)HHOOK hHook =NULL;UINT nHookCount =0;static UCHAR HotKeyMAX_KEY = 0; /hotkeystatic UCHAR HotKeyMaskMAX_KEY = 0; /flag for hotkey, value is VK_CONTRL or VK_NEMU or VK_SHIFTstatic HWND hCallWndMAX_KEY = 0; /window associated with hotkeystatic int KeyCount =0;static UCHAR MaskBits =0; /00000 Ctrl

15、Alt Shift#pragma data_seg()HINSTANCE hins;void VerifyWindow();BEGIN_MESSAGE_MAP(CHookApp, CWinApp)/AFX_MSG_MAP(CHookApp)/ NOTE - the ClassWizard will add and remove mapping macros here./ DO NOT EDIT what you see in these blocks of generated code!/AFX_MSG_MAPEND_MESSAGE_MAP()CHookApp:CHookApp()/ TODO

16、: add construction code here,/ Place all significant initialization in InitInstanceCHookApp theApp;LRESULT CALLBACK KeyboardProc(int nCode,WPARAM wParam,LPARAM lParam) BOOL bProcessed=FALSE;if(HC_ACTION=nCode)if(lParam&0xc0000000)=0xc0000000)/ Key upswitch(wParam)case VK_MENU:MaskBits&=ALTBIT;break;

17、case VK_CONTROL:MaskBits&=CTRLBIT;break;case VK_SHIFT:MaskBits&=SHIFTBIT;break;default: /judge the key and send messagebreak;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=NULL)continue;if(IsWindow(hCallWndindex)&(HotKeyindex=wParam)&(HotKeyMaskindex=MaskBits)SendMessage(hCallWndindex,WM_HOTKE

18、Y,wParam,WM_KEYUP);bProcessed=TRUE;else if(lParam&0xc000ffff)=1) /Key downswitch(wParam)case VK_MENU:MaskBits|=ALTBIT;break;case VK_CONTROL:MaskBits|=CTRLBIT;break;case VK_SHIFT:MaskBits|=SHIFTBIT;break;default: /judge the key and send messagebreak;for(int index=0;indexMAX_KEY;index+)if(hCallWndinde

19、x=NULL)continue;if(IsWindow(hCallWndindex)&(HotKeyindex=wParam)&(HotKeyMaskindex=MaskBits)SendMessage(hCallWndindex,WM_HOTKEY,wParam,WM_KEYDOWN);bProcessed=TRUE;if(!bProcessed)for(int index=0;index1)nHookCount-;return TRUE;BOOL unhooked = UnhookWindowsHookEx(hHook);if(unhooked=TRUE)nHookCount=0;hHoo

20、k=NULL;return unhooked; BOOL _declspec(dllexport) _stdcall AddHotkey(HWND hWnd,UCHAR cKey,UCHAR cMask)BOOL bAdded=FALSE;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=0)hCallWndindex=hWnd;HotKeyindex=cKey;HotKeyMaskindex=cMask;bAdded=TRUE;KeyCount+;break;return bAdded;BOOL _declspec(dllexport) _stdcall DeleteHotkey(HWND hWnd,UCHAR cKey,UCHAR cMask)BOOL bRemoved=FALSE;for(int index=0;indexMAX_KEY;index+)if(hCallWndindex=hWnd)if(HotKeyindex=cKey&HotKeyMaskindex=cMask)hCallWndindex=NULL;HotKeyindex=0;HotKeyMaskindex=0;bRemoved=TRUE;KeyCount-;break;return bRemoved;void