Вот пример простого класса CImage и его использования. Нужно только в примере подставить путь к своей картинке.
Класс CImage - обёртка над стандартным COM интерфейсом IPicture.
Т.е. я отвечаю только за загрузку файла, и всё!
За рисование его отвечает сама система. И об типе файла задумаваться не нужно.
Пробовал на bmp, ico, gif, jpeg, emf, wmf. Отображает.
| Код |
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers
#include <windows.h>
#include <tchar.h>
#include <ocidl.h>
#include <olectl.h>
#define HIMETRIC_INCH 2540
class CImage {
private:
IPicture *m_pPicture;
private:
BOOL Release();
public:
CImage(LPCTSTR szFileName = NULL);
~CImage() { Release(); }
SIZE GetSizeImage() const;
BOOL Draw(HDC hDC, const RECT&) const;
BOOL Load(LPCTSTR szFileName);
};
////////////////////////////////////////////////////////////////////////////////
// other function
////////////////////////////////////////////////////////////////////////////////
SIZE PictureSize(IPicture *pPicture, bool bPixel) {
SIZE size = {0,0};
DWORD dwErrCode = NO_ERROR;
if (!pPicture) {
dwErrCode = ERROR_INVALID_PARAMETER;
} else {
OLE_YSIZE_HIMETRIC hmHeight = 0;
HRESULT hRes = pPicture->get_Height(&hmHeight);
if (FAILED(hRes)) {
dwErrCode = HRESULT_CODE(hRes);
} else {
OLE_XSIZE_HIMETRIC hmWidth = 0;
hRes = pPicture->get_Width(&hmWidth);
if (FAILED(hRes)) {
dwErrCode = HRESULT_CODE(hRes);
} else {
if (bPixel) {
HDC hDC = ::GetDC(::GetDesktopWindow());
size.cx = MulDiv(hmWidth , ::GetDeviceCaps(hDC, LOGPIXELSX), HIMETRIC_INCH);
size.cy = MulDiv(hmHeight, ::GetDeviceCaps(hDC, LOGPIXELSY), HIMETRIC_INCH);
::ReleaseDC(::GetDesktopWindow(), hDC);
} else {
size.cx = hmWidth;
size.cy = hmHeight;
}
}
}
}
::SetLastError(dwErrCode);
return size;
}
HRESULT LoadPictFromFile(IN OUT IPicture **ppPicture, IN LPCTSTR szFile) {
HRESULT hRes = S_OK;
DWORD dwErrCode = NO_ERROR;
if (!ppPicture || !szFile || !szFile[0]) {
hRes = HRESULT_FROM_WIN32(dwErrCode = ERROR_INVALID_PARAMETER);
} else {
*ppPicture = NULL;
}
HANDLE hFile = INVALID_HANDLE_VALUE;
DWORD dwFileSize = 0;
if (SUCCEEDED(hRes)) {
hFile = ::CreateFile(szFile, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
if (hFile == INVALID_HANDLE_VALUE) {
hRes = HRESULT_FROM_WIN32(dwErrCode = ::GetLastError());
} else {
dwFileSize = ::GetFileSize(hFile, NULL);
if (dwFileSize == 0xFFFFFFFF) {
hRes = HRESULT_FROM_WIN32(dwErrCode = ::GetLastError());
}
}
}
HGLOBAL hGlobal = NULL;
LPVOID pData = NULL;
if (SUCCEEDED(hRes)) {
// alloc memory based on file size
hGlobal = ::GlobalAlloc(GMEM_MOVEABLE, dwFileSize);
if (!hGlobal) {
hRes = HRESULT_FROM_WIN32(dwErrCode = ::GetLastError());
} else {
pData = ::GlobalLock(hGlobal);
if (!pData) {
hRes = HRESULT_FROM_WIN32(dwErrCode = ::GetLastError());
}
}
}
DWORD dwNBOR = 0;
if (SUCCEEDED(hRes)) {
// read file and store in global memory
if (!::ReadFile(hFile, pData, dwFileSize, &dwNBOR, NULL) || (dwFileSize!=dwNBOR)) {
hRes = HRESULT_FROM_WIN32(dwErrCode = ::GetLastError());
}
}
LPSTREAM pStm = NULL;
if (SUCCEEDED(hRes)) {
if (SUCCEEDED(hRes)) {
// create IStream* from global memory
hRes = ::CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);
if (SUCCEEDED(hRes) && !pStm) {
hRes = E_FAIL;
}
}
if (SUCCEEDED(hRes)) {
// Create IPicture from image file
hRes = ::OleLoadPicture(pStm, dwFileSize, FALSE, IID_IPicture, (LPVOID*)ppPicture);
if (SUCCEEDED(hRes) && (*ppPicture == NULL)) {
hRes = E_FAIL;
}
}
}
// free data
if (pStm) {
pStm->Release(); pStm = NULL;
}
if (hGlobal) {
::GlobalUnlock(hGlobal);
::GlobalFree(hGlobal);
}
if (hFile != INVALID_HANDLE_VALUE) {
::CloseHandle(hFile);
}
::SetLastError(FAILED(hRes) ? dwErrCode ? dwErrCode : HRESULT_CODE(hRes) : dwErrCode);
return hRes;
}
////////////////////////////////////////////////////////////////////////////////
// implementation CImage
////////////////////////////////////////////////////////////////////////////////
CImage::CImage(LPCTSTR szFileName) : m_pPicture (NULL)
{
if (szFileName) {
Load(szFileName);
}
}
BOOL CImage::Load(LPCTSTR szFileName) {
BOOL bRes = TRUE;
DWORD dwErrCode = NO_ERROR;
if (!szFileName || !szFileName[0]) {
dwErrCode = ERROR_INVALID_PARAMETER;
bRes = FALSE;
} else {
HANDLE hImageNew = NULL;
IPicture *pPicture = NULL;
bRes = SUCCEEDED(::LoadPictFromFile(&pPicture, szFileName));
if (!bRes) {
dwErrCode = ::GetLastError();
} else {
Release();
m_pPicture = pPicture;
}
}
::SetLastError(dwErrCode);
return bRes;
}
BOOL CImage::Release() {
BOOL bRes = !!m_pPicture;
if (m_pPicture) {
m_pPicture->Release();
m_pPicture = NULL;
}
return bRes;
}
SIZE CImage::GetSizeImage() const {
return PictureSize(m_pPicture, true);
}
BOOL CImage::Draw(HDC hDC, const RECT &rect) const {
BOOL bRes = TRUE;
DWORD dwErrCode = NO_ERROR;
if (m_pPicture) {
//SIZE sizeP = PictureSize(m_pPicture, true);
SIZE sizeH = PictureSize(m_pPicture, false);
//HRESULT hRes = m_pPicture->Render(hDC, 0, 0, sizeP.cx, sizeP.cy, 0, sizeH.cy, sizeH.cx, -sizeH.cy, &rect);
HRESULT hRes = m_pPicture->Render(hDC, rect.left, rect.top, rect.right-rect.left, rect.bottom-rect.top, 0, sizeH.cy, sizeH.cx, -sizeH.cy, &rect);
if (FAILED(hRes)) {
dwErrCode = HRESULT_CODE(hRes);
}
}
::SetLastError(dwErrCode);
return bRes;
}
////////////////////////////////////////////////////////////////////////////////
// main part
////////////////////////////////////////////////////////////////////////////////
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int nCmdShow) {
WNDCLASSEX wcex = {
sizeof(WNDCLASSEX), // UINT cbSize;
CS_HREDRAW | CS_VREDRAW, // UINT style;
(WNDPROC)WndProc, // WNDPROC lpfnWndProc;
0, // int cbClsExtra;
0, // int cbWndExtra;
hInstance, // HINSTANCE hInstance;
NULL, // HICON hIcon;
LoadCursor(NULL, IDC_ARROW), // HCURSOR hCursor;
GetSysColorBrush(COLOR_BTNFACE), // HBRUSH hbrBackground;
NULL, // LPCSTR lpszMenuName;
_T("TestImageWindowClass"), // LPCSTR lpszClassName;
NULL // HICON hIconSm;
};
RegisterClassEx(&wcex);
HWND hWnd = CreateWindow(_T("TestImageWindowClass"), _T("Test CImage"), WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
MSG msg;
while (GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
switch (message) {
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
RECT rt; GetClientRect(hWnd, &rt);
static CImage img(_T("c:\\img\\index_r1_c3.jpg"));
img.Draw(hdc, rt);
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
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(чувствую себя довольно неуютно
)