怎样读取硬盘上指定位置的位图文件？(VC)

Question

HBITMAP bitmap;bitmap=(HBITMAP)LoadImage(AfxGetInstanceHandle(),"SAMPLE.BMP",IMAGE_BITMAP,0,0,LR_LOADFROMFILE|LR_CREATEDIBSECTION);
ASSERT(bitmap);

Answer 1

HBITMAP m_hBmp1;
m_hBmp1 = (HBITMAP)LoadImage(NULL, "c:\\123.bmp", IMAGE_BITMAP, 0, 0, 
LR_LOADFROMFILE | LR_CREATEDIBSECTION | LR_DEFAULTSIZE); 绘制
DrawBitmap( &dc, m_hBmp1, NULL, 0, 0 );
void DrawBitmap( CDC *pDC, HBITMAP hBitmap, HPALETTE hPal, int xDest, int yDest )
{
// Get logical coordinates
BITMAP bm;
::GetObject( hBitmap, sizeof( bm ), &bm );
CPoint size( bm.bmWidth, bm.bmHeight );
pDC->DPtoLP(&size); CPoint org(0,0);
pDC->DPtoLP(&org); // Create a memory DC compatible with the destination DC
CDC memDC;
memDC.CreateCompatibleDC( pDC );
memDC.SetMapMode( pDC->GetMapMode() );

//memDC.SelectObject( &bitmap );
HBITMAP hBmOld = (HBITMAP)::SelectObject( memDC.m_hDC, hBitmap );


// Select and realize the palette
if( hPal && pDC->GetDeviceCaps(RASTERCAPS) & RC_PALETTE)
{
SelectPalette( pDC->GetSafeHdc(), hPal, FALSE );
pDC->RealizePalette();
}
pDC->BitBlt(xDest, yDest, size.x, size.y, &memDC, org.x, org.y, SRCCOPY); ::SelectObject( memDC.m_hDC, hBmOld );
}

Answer 2

Method 1:
 HBITMAP CDandelionDlg::BufferToBITMAP(LPSTR path)
{
LPSTR p;
DWORD size;
CFile pf; pf.Open(path,CFile::modeRead);
size=pf.GetLength();
p=new char[size];
pf.ReadHuge(p,size);
pf.Close();
HBITMAP hBmp;
LPSTR hDIB,lpBuffer=p;
LPVOID lpDIBBits;
BITMAPFILEHEADER bmfHeader;
DWORD bmfHeaderLen; bmfHeaderLen=sizeof(bmfHeader);
strncpy((LPSTR)&bmfHeader,(LPSTR)lpBuffer,bmfHeaderLen);
if(bmfHeader.bfType!=((WORD)('M'<<8)|'B'))return NULL;
hDIB=lpBuffer+bmfHeaderLen;
BITMAPINFOHEADER &bmiHeader=*(LPBITMAPINFOHEADER)hDIB;
BITMAPINFO &bmInfo=*(LPBITMAPINFO)hDIB;
int nColors=bmiHeader.biClrUsed ? bmiHeader.biClrUsed : 1<<bmiHeader.biBitCount;
if(bmInfo.bmiHeader.biBitCount>8)
lpDIBBits=(LPVOID)((LPDWORD)(bmInfo.bmiColors+bmInfo.bmiHeader.biClrUsed)+
((bmInfo.bmiHeader.biCompression==BI_BITFIELDS) ? 3 : 0));
else
lpDIBBits=(LPVOID)(bmInfo.bmiColors+nColors);
CClientDC dc(this);
hBmp=CreateDIBitmap(dc.m_hDC,&bmiHeader,CBM_INIT,lpDIBBits,&bmInfo,DIB_RGB_COLORS); delete[] p;
return hBmp;
}Method 2:
 CoInitialize(NULL);
 CComQIPtr<IPicture> ppic;
 PICTDESC pd;
 ZeroMemory(&pd,sizeof(PICTDESC));
 pd.cbSizeofstruct=sizeof(PICTDESC);
 pd.picType=PICTYPE_BITMAP;
 CFile pf;
 pf.Open("c:\\008.jpg",CFile::modeReadWrite);
 CArchive::bNoFlushOnDelete),sr(&sf,CArchive::store);
 CArchiveStream arcstream(&ar),src(&sr);
 OleLoadPicture((IStream*)(&arcstream),0, FALSE,IID_IPicture,(void**)&ppic);
 assert(ppic);
 
 RECT r;
 GetWindowRect(&r);
 CRect rect(r);
 long height,width;
 ppic->get_Height(&height);
 ppic->get_Width(&width);
 ppic->Render(::GetDC(0),rect.left,rect.top,rect.Width(),rect.Height(),0,height,width,-height,&rect);
 ppic.Release();
 CoUninitialize();
//#include <assert.h>
//#include <afxpriv2.h>

Answer 3

HBITMAP m_hBitmap;
m_hBitmap=(HBITMAP)LoadImage(NULL,lpszImageFile,IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
那个句柄只用来标识该在那个范围里读取，如果从磁盘文件读取，我就把她设为NULL

Answer 4

建议使用IPicture接口来读，正在研究这个接口。

Answer 5

BOOL LoadBitmap(LPCTSTR lpszResourceName);