DLL 内存共享

DLL 中可以将其设置一段共享内存然后，和别的程序进行信息交互

  下面一段程序时设置一个共享的内存，然后提供三个函数对其操作，

一个增加字符AddString

一个删除字符DeleteString

一个获得字符GetStrings

 

/*----------------------------------------------------------------------------
STRLIB.H header file
-----------------------------------------------------------------------------*/

 

#ifdef __cplusplus
#define EXPORT extern "C" __declspec (dllexport)
#else
#define EXPORT __declspec (dllexport)
#endif
// The maximum number of strings STRLIB will store and their lengths
#define MAX_STRINGS 256
#define MAX_LENGTH 63
// The callback function type definition uses generic strings
typedef BOOL (CALLBACK * GETSTRCBA) (PSTR, PVOID) ;
typedef BOOL (CALLBACK * GETSTRCBW) (PCTSTR, PVOID) ;
#if UNICODE
#define GETSTRCB GETSTRCBW
#else
#define GETSTRCB GETSTRCBA
#endif
// Each function has ANSI and Unicode versions
EXPORT BOOL CALLBACK AddStringA (PCSTR) ;
EXPORT BOOL CALLBACK AddStringW (PCWSTR) ;
EXPORT BOOL CALLBACK DeleteStringA (PCSTR) ;
EXPORT BOOL CALLBACK DeleteStringW (PCWSTR) ;
EXPORT int CALLBACK GetStringsA (GETSTRCB, PVOID) ;
EXPORT int CALLBACK GetStringsW (GETSTRCB, PVOID) ;
// Use the correct version depending on the UNICODE identifier
#ifdef UNICODE
#define AddString AddStringW
#define DeleteString DeleteStringW
#define GetStrings GetStringsW
#else
#define AddString AddStringA
#define DeleteString DeleteStringA
#define GetStrings GetStringsA
#endif

 

/*---------------------------------------------------------------------------
STRLIB.C - Library module for STRPROG program
(c) Charles Petzold, 1998
----------------------------------------------------------------------------*/
#include <windows.h>
#include <wchar.h> // for wide-character string functions
#include "strlib.h"

// shared memory section (requires /SECTION:shared,RWS in link options)

#pragma data_seg ("shared")
int iTotal = 0 ;
WCHAR szStrings [MAX_STRINGS][MAX_LENGTH + 1] = { '/0' } ;
#pragma data_seg ()

#pragma comment(linker,"/SECTION:shared,RWS")

 

 

int WINAPI DllMain (HINSTANCE hInstance, DWORD fdwReason, PVOID pvReserved)
{
    return TRUE ;
}
EXPORT BOOL CALLBACK AddStringA (PCSTR pStringIn)
{
    BOOL bReturn ;
    int iLength ;
    PWSTR pWideStr ;
    // Convert string to Unicode and call AddStringW
    iLength = MultiByteToWideChar (CP_ACP, 0, pStringIn, -1, NULL, 0) ;
    pWideStr = (PWSTR)malloc (iLength) ;
    MultiByteToWideChar (CP_ACP, 0, pStringIn, -1, pWideStr, iLength) ;
    bReturn = AddStringW (pWideStr) ;
    free (pWideStr) ;
    return bReturn ;
}
EXPORT BOOL CALLBACK AddStringW (PCWSTR pStringIn)
{
    PWSTR pString ;
    int i, iLength ;
    if (iTotal == MAX_STRINGS - 1)
        return FALSE ;
    if ((iLength = wcslen (pStringIn)) == 0)
        return FALSE ;
    // Allocate memory for storing string, copy it, convert to uppercase
    pString = (PWSTR)malloc (sizeof (WCHAR) * (1 + iLength)) ;
    wcscpy (pString, pStringIn) ;
    _wcsupr (pString) ;
    // Alphabetize the strings
    for (i = iTotal ; i > 0 ; i--)
    {
        if (wcscmp (pString, szStrings[i - 1]) >= 0)
            break ;
        wcscpy (szStrings[i], szStrings[i - 1]) ;
    }
    wcscpy (szStrings[i], pString) ;
    iTotal++ ;
    free (pString) ;
    return TRUE ;
}
EXPORT BOOL CALLBACK DeleteStringA (PCSTR pStringIn)
{
    BOOL bReturn ;
    //Defoe.Tu tyysoft@yahoo.com.cn Windows 程序设计 PDF 美化版
    int iLength ;
    PWSTR pWideStr ;
    // Convert string to Unicode and call DeleteStringW
    iLength = MultiByteToWideChar (CP_ACP, 0, pStringIn, -1, NULL, 0) ;
    pWideStr = (PWSTR)malloc (iLength) ;
    MultiByteToWideChar (CP_ACP, 0, pStringIn, -1, pWideStr, iLength) ;
    bReturn = DeleteStringW (pWideStr) ;
    free (pWideStr) ;
    return bReturn ;
}
EXPORT BOOL CALLBACK DeleteStringW (PCWSTR pStringIn)
{
    int i, j ;
    if (0 == wcslen (pStringIn))
        return FALSE ;
    for (i = 0 ; i < iTotal ; i++)
    {
        if (_wcsicmp (szStrings[i], pStringIn) == 0)
            break ;
    }
    // If given string not in list, return without taking action
    if (i == iTotal)
        return FALSE ;
    // Else adjust list downward
    for (j = i ; j < iTotal ; j++)
        wcscpy (szStrings[j], szStrings[j + 1]) ;
    szStrings[iTotal--][0] = '/0' ;
    return TRUE ;
}
EXPORT int CALLBACK GetStringsA (GETSTRCB pfnGetStrCallBack, PVOID pParam)
{
    BOOL bReturn ;
    int i, iLength ;
    PSTR pAnsiStr ;
    for (i = 0 ; i < iTotal ; i++)
    {
        // Convert string from Unicode
        iLength = WideCharToMultiByte ( CP_ACP, 0, szStrings[i], -1, NULL, 0, NULL, NULL) ;
        pAnsiStr = (PSTR)malloc (iLength) ;
        WideCharToMultiByte ( CP_ACP, 0, szStrings[i], -1, pAnsiStr, iLength, NULL, NULL) ;
        // Call callback function
       // bReturn = pfnGetStrCallBack (pAnsiStr, pParam) ;
        if (bReturn == FALSE)
            return i + 1 ;
        free (pAnsiStr) ;
    }
    return iTotal ;
}
EXPORT int CALLBACK GetStringsW (GETSTRCB pfnGetStrCallBack, PVOID pParam)
{
    BOOL bReturn ;
    int i ;
    for (i = 0 ; i < iTotal ; i++)
    {
        bReturn = pfnGetStrCallBack (szStrings[i], pParam) ;
        if (bReturn == FALSE)
            return i + 1 ;
     }
    return  iTotal ;
}

 

测试文件

/*----------------------------------------------------------------------------
STRPROG.C - Program using STRLIB dynamic-link library
(c) Charles Petzold, 1998
-----------------------------------------------------------------------------*/
#include <windows.h>
#include "strlib.h"
#include "resource.h"
typedef struct
{
    HDC hdc ;
    int xText ;
    int yText ;
    int xStart ;
    int yStart ;
    int xIncr ;
    int yIncr ;
    int xMax ;
    int yMax ;
}
CBPARAM ;
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
TCHAR szAppName [] = TEXT ("StrProg") ;
TCHAR szString [MAX_LENGTH + 1] ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
    HWND hwnd ;
    MSG msg ;
    WNDCLASS wndclass ;
    wndclass.style = CS_HREDRAW | CS_VREDRAW ;
    wndclass.lpfnWndProc = WndProc ;
    wndclass.cbClsExtra = 0 ;
    wndclass.cbWndExtra = 0 ;
    wndclass.hInstance = hInstance ;
    wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
    wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
    wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
    wndclass.lpszMenuName = szAppName ;
    wndclass.lpszClassName = szAppName ;
    if (!RegisterClass (&wndclass))
    {
        MessageBox ( NULL, TEXT ("This program requires Windows NT!"),
            szAppName, MB_ICONERROR) ;
        return 0 ;
    }
    hwnd = CreateWindow (szAppName, TEXT ("DLL Demonstration Program"),
        WS_OVERLAPPEDWINDOW,
        //Defoe.Tu tyysoft@yahoo.com.cn Windows 程序设计 PDF 美化版
        CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, CW_USEDEFAULT,
        NULL, NULL, hInstance, NULL) ;
    ShowWindow (hwnd, iCmdShow) ;
    UpdateWindow (hwnd) ;
    while (GetMessage (&msg, NULL, 0, 0))
    {
        TranslateMessage (&msg) ;
        DispatchMessage (&msg) ;
    }
    return msg.wParam ;
}
BOOL CALLBACK DlgProc (HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_INITDIALOG:
        SendDlgItemMessage (hDlg, IDC_STRING, EM_LIMITTEXT, MAX_LENGTH, 0) ;
        return TRUE ;
    case WM_COMMAND:
        switch (wParam)
        {
        case IDOK:
            GetDlgItemText (hDlg, IDC_STRING, szString, MAX_LENGTH) ;
            EndDialog (hDlg, TRUE) ;
            return TRUE ;
        case IDCANCEL:
            EndDialog (hDlg, FALSE) ;
            return TRUE ;
        }
    }
    return FALSE ;
}
BOOL CALLBACK GetStrCallBack (PTSTR pString, CBPARAM * pcbp)
{
    TextOut ( pcbp->hdc, pcbp->xText, pcbp->yText,
        pString, lstrlen (pString)) ;
    if ((pcbp->yText += pcbp->yIncr) > pcbp->yMax)
    {
        pcbp->yText = pcbp->yStart ;
        if ((pcbp->xText += pcbp->xIncr) > pcbp->xMax)
            return FALSE ;
    }
    return TRUE ;
}
LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static HINSTANCE hInst ;
    static int cxChar, cyChar, cxClient, cyClient ;
    static UINT iDataChangeMsg ;
    CBPARAM cbparam ;
    HDC hdc ;
    PAINTSTRUCT ps ;
    TEXTMETRIC tm ;
    switch (message)
    {
    case WM_CREATE:
        hInst = ((LPCREATESTRUCT) lParam)->hInstance ;
        hdc = GetDC (hwnd) ;
        GetTextMetrics (hdc, &tm) ;
        //Defoe.Tu tyysoft@yahoo.com.cn Windows 程序设计 PDF 美化版
        cxChar = (int) tm.tmAveCharWidth ;
        cyChar = (int) (tm.tmHeight + tm.tmExternalLeading) ;
        ReleaseDC (hwnd, hdc) ;
        // Register message for notifying instances of data changes
        iDataChangeMsg = RegisterWindowMessage (TEXT ("StrProgDataChange")) ;
        return 0 ;
    case WM_COMMAND:
        switch (wParam)
        {
        case IDM_ENTER:
            if (DialogBox (hInst, TEXT ("EnterDlg"), hwnd, &DlgProc))
            {
                if (AddString (szString))
                    PostMessage (HWND_BROADCAST, iDataChangeMsg, 0, 0) ;
                else
                    MessageBeep (0) ;
            }
            break ;
        case IDM_DELETE:
            if (DialogBox (hInst, TEXT ("DeleteDlg"), hwnd, &DlgProc))
            {
                if (DeleteString (szString))
                    PostMessage (HWND_BROADCAST, iDataChangeMsg, 0, 0) ;
                else
                    MessageBeep (0) ;
            }
            break ;
        }
        return 0 ;
    case WM_SIZE:
        cxClient = (int) LOWORD (lParam) ;
        cyClient = (int) HIWORD (lParam) ;
        return 0 ;
    case WM_PAINT:
        hdc = BeginPaint (hwnd, &ps) ;
        cbparam.hdc = hdc ;
        cbparam.xText= cbparam.xStart = cxChar ;
        cbparam.yText= cbparam.yStart = cyChar ;
        cbparam.xIncr= cxChar * MAX_LENGTH ;
        cbparam.yIncr= cyChar ;
        cbparam.xMax = cbparam.xIncr * (1 + cxClient / cbparam.xIncr) ;
        cbparam.yMax = cyChar * (cyClient / cyChar - 1) ;
        GetStrings ((GETSTRCB) GetStrCallBack, (PVOID) &cbparam) ;
        EndPaint (hwnd, &ps) ;
        return 0 ;
    case WM_DESTROY:
        PostQuitMessage (0) ;
        return 0 ;
    default:
        if (message == iDataChangeMsg)
            InvalidateRect (hwnd, NULL, TRUE) ;
        break ;
    }
    return DefWindowProc (hwnd, message, wParam, lParam) ;
}

 

resource.h

//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ generated include file.
// Used by StrProg.rc
//
#define IDC_STRING 1000
#define IDM_ENTER 40001
#define IDM_DELETE 40002
#define IDC_STATIC -1

// Next default values for new objects
//
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE        103
#define _APS_NEXT_COMMAND_VALUE         40002
#define _APS_NEXT_CONTROL_VALUE         1003
#define _APS_NEXT_SYMED_VALUE           101
#endif
#endif

 

// Microsoft Visual C++ generated resource script.
//
#include "resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// 中文(中华人民共和国) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_CHS)
#ifdef _WIN32
LANGUAGE LANG_CHINESE, SUBLANG_CHINESE_SIMPLIFIED
#pragma code_page(936)
#endif //_WIN32

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE
BEGIN
    "resource.h/0"
END

2 TEXTINCLUDE
BEGIN
    "#include ""afxres.h""/r/n"
    "/0"
END

3 TEXTINCLUDE
BEGIN
    "/r/n"
    "/0"
END

#endif    // APSTUDIO_INVOKED

/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//

ENTERDLG DIALOG DISCARDABLE 20, 20, 186, 47
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Enter"
FONT 8, "MS Sans Serif"
BEGIN
LTEXT "&Enter:",IDC_STATIC,7,7,26,9
EDITTEXT IDC_STRING,31,7,148,12,ES_AUTOHSCROLL
DEFPUSHBUTTON "OK",IDOK,32,26,50,14
PUSHBUTTON "Cancel",IDCANCEL,104,26,50,14
END
DELETEDLG DIALOG DISCARDABLE 20, 20, 186, 47
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Delete"
FONT 8, "MS Sans Serif"
BEGIN
LTEXT "&Delete:",IDC_STATIC,7,7,26,9
EDITTEXT IDC_STRING,31,7,148,12,ES_AUTOHSCROLL
DEFPUSHBUTTON "OK",IDOK,32,26,50,14
PUSHBUTTON "Cancel",IDCANCEL,104,26,50,14
END

/////////////////////////////////////////////////////////////////////////////
//
// DESIGNINFO
//

#ifdef APSTUDIO_INVOKED
GUIDELINES DESIGNINFO
BEGIN
    IDD_DIALOG1, DIALOG
    BEGIN
        LEFTMARGIN, 7
        RIGHTMARGIN, 179
        TOPMARGIN, 7
        BOTTOMMARGIN, 83
    END
END
#endif    // APSTUDIO_INVOKED

/////////////////////////////////////////////////////////////////////////////
//
// Menu
//
STRPROG MENU DISCARDABLE
BEGIN
MENUITEM "&Enter!", IDM_ENTER
MENUITEM "&Delete!", IDM_DELETE
END

/////////////////////////////////////////////////////////////////////////////
//
// String Table
//

#endif    // 中文(中华人民共和国) resources
/////////////////////////////////////////////////////////////////////////////

 

#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//

/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

 

 

这个文件可运行的。

 

自己把编好的程序多运行几个实体，看看效果吧！