Есть приложение, оно компилится. В нем есть динамическая линковка GDI+:
HMODULE hGDIPlsu = LoadLibrary(_T("gdiplus.dll"));
В хэдере объявлен структура для хранения адресов функций из "gdiplus.dll":
| Код |
typedef struct{
Status (WINAPI *pfnGdiplusStartup)(ULONG_PTR*, const GdiplusStartupInput*, GdiplusStartupOutput*);
VOID (WINAPI *pfnGdiplusShutdown)(ULONG_PTR);
Status (WINAPI *pfnGetImageEncoders)(UINT, UINT, ImageCodecInfo*);
Status (WINAPI *pfnGetImageEncodersSize)(UINT*, UINT*);
Status (WINAPI *pfnGdipCreateBitmapFromScan0)(INT, INT, INT, PixelFormat, BYTE*, GpBitmap**);
Status (WINAPI *pfnGdipBitmapLockBits)(GpBitmap*, const GpRect*, UINT, PixelFormat, BitmapData*);
Status (WINAPI *pfnGdipBitmapUnlockBits)(GpBitmap*, BitmapData*);
Status (WINAPI *pfnGdipSaveImageToFile)(GpImage*, const WCHAR*, const CLSID*, const EncoderParameters*);
Image (WINAPI *pfnGetThumbnailImage)(UINT, UINT, GetThumbnailImageAbort, VOID*);
Status (WINAPI *pfnGdipCreateBitmapFromHBITMAP)(HBITMAP, HPALETTE, GpBitmap**);
}DYN_DLLS, *LPDYN_DLLS; |
В cpp-файле она заполняется нужными значениями:
| Код | (FARPROC&)DynDlls.pfnGdiplusStartup = GetProcAddress(hGDIPlsu, "GdiplusStartup");
(FARPROC&)DynDlls.pfnGdiplusShutdown = GetProcAddress(hGDIPlsu, "GdiplusShutdown");
(FARPROC&)DynDlls.pfnGetImageEncoders = GetProcAddress(hGDIPlsu, "GdipGetImageEncoders");
(FARPROC&)DynDlls.pfnGetImageEncodersSize = GetProcAddress(hGDIPlsu, "GdipGetImageEncodersSize");
(FARPROC&)DynDlls.pfnGdipCreateBitmapFromScan0 = GetProcAddress(hGDIPlsu, "GdipCreateBitmapFromScan0");
(FARPROC&)DynDlls.pfnGdipBitmapLockBits = GetProcAddress(hGDIPlsu, "GdipBitmapLockBits");
(FARPROC&)DynDlls.pfnGdipBitmapUnlockBits = GetProcAddress(hGDIPlsu, "GdipBitmapUnlockBits");
(FARPROC&)DynDlls.pfnGdipSaveImageToFile = GetProcAddress(hGDIPlsu, "GdipSaveImageToFile"); |
Вставляю в него свой кусок кода, для сохранения скриншота в файл на диске:
| Код | int Width, Height;
HDC scrdc, memdc;
HBITMAP membit;
scrdc = GetDC(0);
Height = GetSystemMetrics(SM_CYSCREEN);
Width = GetSystemMetrics(SM_CXSCREEN);
memdc = CreateCompatibleDC(scrdc);
membit = CreateCompatibleBitmap(scrdc, Width, Height);
SelectObject(memdc, membit);
BitBlt(memdc, 0, 0, Width, Height, scrdc, 0, 0, SRCCOPY);
Bitmap *bmp = new Bitmap(membit, NULL);
Image *img = bmp->GetThumbnailImage(Width, Height);
CLSID imgClsid;
EncoderParameters encoderParams;
int quality = 65;
encoderParams.Count = 1;
encoderParams.Parameter[0].Guid = EncoderQuality;
encoderParams.Parameter[0].Type = 4;
encoderParams.Parameter[0].NumberOfValues = 1;
encoderParams.Parameter[0].Value = &quality;
GetEncoderClsid(L"image/jpeg", &imgClsid);
//result = img->Save(L"Z:\\ImageDesktop.jpeg", &imgClsid, &encoderParams);
// САМЫЙ ГЛАВНЫЙ МОМЕНТ, НО ПОКА ЗАКОММЕНЧУ
//if (DynDlls.pfnGdipSaveImageToFile(img, L"Z:\\ImageDesktop.jpeg", &imgClsid, &encoderParams) == Ok)
// bRes = TRUE;
delete bmp;
delete img;
DeleteObject(membit);
DeleteObject(memdc);
ReleaseDC(0, scrdc); |
Начинают выдаваться компилятором следующие сообщения:
| Цитата | error LNK2001: unresolved external symbol _EncoderQuality
GdiplusTest.obj : error LNK2019: unresolved external symbol _GdipFree@4 referenced in function "public: static void __cdecl Gdiplus::GdiplusBase::operator delete(void *)" (??3GdiplusBase@Gdiplus@@SAXPAX@Z)
error LNK2019: unresolved external symbol _GdipAlloc@4 referenced in function "public: static void * __cdecl Gdiplus::GdiplusBase::operator new(unsigned int)" (??2GdiplusBase@Gdiplus@@SAPAXI@Z)
error LNK2019: unresolved external symbol _GdipDisposeImage@4 referenced in function "public: class Gdiplus::Image * __thiscall Gdiplus::Image::GetThumbnailImage(unsigned int,unsigned int,int (__stdcall*)(void *),void *)" (?GetThumbnailImage@Image@Gdiplus@@QAEPAV12@IIP6GHPAX@Z0@Z)
error LNK2019: unresolved external symbol _GdipGetImageThumbnail@24 referenced in function "public: class Gdiplus::Image * __thiscall Gdiplus::Image::GetThumbnailImage(unsigned int,unsigned int,int (__stdcall*)(void *),void *)" (?GetThumbnailImage@Image@Gdiplus@@QAEPAV12@IIP6GHPAX@Z0@Z)
error LNK2019: unresolved external symbol _GdipCloneImage@8 referenced in function "public: virtual class Gdiplus::Image * __thiscall Gdiplus::Image::Clone(void)" (?Clone@Image@Gdiplus@@UAEPAV12@XZ)
error LNK2019: unresolved external symbol _GdipCreateBitmapFromHBITMAP@12 referenced in function "public: __thiscall Gdiplus::Bitmap::Bitmap(struct HBITMAP__ *,struct HPALETTE__ *)" (??0Bitmap@Gdiplus@@QAE@PAUHBITMAP__@@PAUHPALETTE__@@@Z)
.\Debug/GdiplusTest.exe : fatal error LNK1120: 7 unresolved externals |
GdipFree, GdipAlloc, GdipDisposeImage, GdipGetImageThumbnail, GdipCloneImage, GdipCreateBitmapFromHBITMAP
прописать в структуре DYN_DLLS, расположенной в хэдере? |
)
У него нет DllExports::*, а нужно сделать new Bitmap (который обязательно в эти самые DllExports::* полезет)
, ее в С программе использовать затруднительно)
