绕口的问题！！

DLL在被不同的进程加载时进入不同的地址空间，数据是不能通过这种方式传递的，用IPC机制，如共享内存。

有没有具体的源码？
我已经用了共享内存，但不知道为什么A 能读 C 的数据，C 读不了 B的
（当然 A是不能直接读 B的数据）

问题在于 A和C 是我写的，但B是别人的，
A C 可以共享内存，而 B 不行啊

C给A发消息时使用WM_COPYDATA,MS使用COPYDATASTRUCT可在两个进程之间传递数据。

Zark(金陵五月)的没有问题，可以在不同的进程间传递数据。

谢谢Zark(金陵五月)：有没有源码？

抱歉,没有CODE,如果你把你的发给我,我可以帮你改一改.

DLL使用的是进程的内存,应该是可以传到外面去的.问题可能出在内存定位(memrory allocation)上,如果你的test code不是很长的话,贴出来看看,如果很长,你愿意的话,可以发给我[email protected]

你可在DLL文件中定义一个共享函数,变量好象不行,对于任何一个调用它的进程都使用同样的地址空间,这样的进程最好只有你使用,不然多个会使得变量值不确定.

DLL c test code:BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
)
{
    switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
    }
    return TRUE;
}BOOL MySendMessage(HWND hDestination,HWND hSource,LPSTR szText)
{
if(!hDestination || !hSource)
return FALSE; TCHAR szTextFromDll[MAX_PATH]=_T("Text from Dll"); COPYDATASTRUCT data;
data.dwData=0;
data.cbData=lstrlen(szText);
data.lpData=szText; if(!SendMessage(hDestination,WM_COPYDATA,(WPARAM)hSource,(LPARAM)&data))
{
int i=GetLastError();
}

data.dwData=0;
data.cbData=lstrlen(szTextFromDll);
data.lpData=szTextFromDll;
if(!SendMessage(hDestination,WM_COPYDATA,(WPARAM)hSource,(LPARAM)&data))
{
int i=GetLastError();
}

return TRUE;
}

Process A code:// Global Variables:
HINSTANCE hInst; // current instance
TCHAR szTitle[MAX_LOADSTRING]; // The title bar text
TCHAR szWindowClass[MAX_LOADSTRING]; // The title bar text// Foward 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 About(HWND, UINT, WPARAM, LPARAM);int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
// TODO: Place code here.
MSG msg;
HACCEL hAccelTable; // Initialize global strings
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadString(hInstance, IDC_PROGA, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance); // Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
} hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_PROGA); // Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
} return msg.wParam;
}//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage is 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)WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, (LPCTSTR)IDI_PROGA);
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = (LPCSTR)IDC_PROGA;
wcex.lpszClassName = _T("ProgA");
wcex.hIconSm = LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL); return RegisterClassEx(&wcex);
}//
//   FUNCTION: InitInstance(HANDLE, 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)
{
   HWND hWnd;   hInst = hInstance; // Store instance handle in our global variable   hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);   if (!hWnd)
   {
      return FALSE;
   }   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);   return TRUE;
}//
//  FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
//  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)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
TCHAR szHello[MAX_LOADSTRING],szTemp[MAX_LOADSTRING];
LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);
HWND hWndB=NULL; switch (message)
{
case WM_COMMAND:
wmId    = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_SEND:
wsprintf(szTemp,_T("%s"),_T("Here is string sending from ProgA"));
hWndB=FindWindow(_T("ProgB"),NULL);
if(!hWndB)
break;
MySendMessage(hWndB,hWnd,szTemp);
break;
case IDM_ABOUT:
   DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
   break;
case IDM_EXIT:
   DestroyWindow(hWnd);
   break;
default:
   return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
RECT rt;
GetClientRect(hWnd, &rt);
DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER);
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}

Process B code:#include "stdafx.h"
#include "resource.h"#define MAX_LOADSTRING 100// Global Variables:
HINSTANCE hInst; // current instance
TCHAR szTitle[MAX_LOADSTRING]; // The title bar text
TCHAR szWindowClass[MAX_LOADSTRING]; // The title bar text// Foward 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 About(HWND, UINT, WPARAM, LPARAM);int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
// TODO: Place code here.
MSG msg;
HACCEL hAccelTable; // Initialize global strings
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadString(hInstance, IDC_PROGB, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance); // Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
} hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_PROGB); // Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
} return msg.wParam;
}//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage is 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)WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, (LPCTSTR)IDI_PROGB);
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = (LPCSTR)IDC_PROGB;
wcex.lpszClassName = _T("ProgB");
wcex.hIconSm = LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL); return RegisterClassEx(&wcex);
}//
//   FUNCTION: InitInstance(HANDLE, 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)
{
   HWND hWnd;   hInst = hInstance; // Store instance handle in our global variable   hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);   if (!hWnd)
   {
      return FALSE;
   }   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);   return TRUE;
}//
//  FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
//  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)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
TCHAR szHello[MAX_LOADSTRING];
LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING); COPYDATASTRUCT *pData;
TCHAR szBuf[MAX_PATH]={_T('\0')}; switch (message)
{
case WM_COMMAND:
wmId    = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
   DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
   break;
case IDM_EXIT:
   DestroyWindow(hWnd);
   break;
default:
   return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
RECT rt;
GetClientRect(hWnd, &rt);
DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER);
EndPaint(hWnd, &ps);
break;
case WM_COPYDATA:
pData=(COPYDATASTRUCT*)lParam;
lstrcpyn(szBuf,(LPCTSTR)pData->lpData,pData->cbData+1); MessageBox(hWnd,szBuf,_T(""),MB_OK); break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}// Mesage handler for about box.
LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_INITDIALOG:
return TRUE; case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam));
return TRUE;
}
break;
}
    return FALSE;
}

调试易

绕口的问题！！

解决方案 »