how do i copy a CImage DIB to clipboard

[User 9469396]

im trying to copy a cimage dib to the clipboard. the second memcpy fails with a read access violation. can anyone help?

CImage tmpImage = pDoc->m_imageArray[0];

int w = tmpImage.GetWidth();
int h = tmpImage.GetHeight();
int Bpp = tmpImage.GetBPP();
 
BITMAPINFOHEADER bmInfohdr;
bmInfohdr.biSize = sizeof(BITMAPINFOHEADER);
bmInfohdr.biWidth = w;
bmInfohdr.biHeight = -h;
bmInfohdr.biPlanes = 1;
bmInfohdr.biBitCount = Bpp;
bmInfohdr.biCompression = BI\_RGB;
bmInfohdr.biSizeImage = w\*h\*Bpp;
bmInfohdr.biXPelsPerMeter = 0;
bmInfohdr.biYPelsPerMeter = 0;
bmInfohdr.biClrUsed = 0;
bmInfohdr.biClrImportant = 0;
 
BITMAPINFO bmInfo;
bmInfo.bmiHeader = bmInfohdr;
bmInfo.bmiColors\[0\].rgbBlue=255;
 
 
void\* pBits = tmpImage.GetBits();
HANDLE hData = ::GlobalAlloc (GMEM\_MOVEABLE, sizeof(BITMAPINFO) + w \* h \* 3);
LPVOID pData = (LPVOID) ::GlobalLock (hData);
LPBYTE p\_imagebits;
p\_imagebits  = (LPBYTE)pData + sizeof(BITMAPINFO);


memcpy(pData,&bmInfo,sizeof(BITMAPINFO));
 
       
DWORD dwBytes = ((DWORD) w \* Bpp) / 32;

if(((DWORD) w \* Bpp) % 32) {
   dwBytes++;
}
dwBytes \*= 4;

unsigned long m\_dwSizeImage = dwBytes \* h; // no compression
 
 
memcpy (p\_imagebits, pBits, m\_dwSizeImage);


::GlobalUnlock (hData);
 
COleDataSource\* pods = new COleDataSource;
pods->CacheGlobalData (CF\_DIB, hData);
pods->SetClipboard ();

[chaau]

It fails because the memory allocated by GlobalAlloc is not enough. See, how you use sizeof(BITMAPINFO) + w * h * 3 value to allocate memory, and then you are trying to calculate the m_dwSizeImage value, which is much greater then requested. You have got two options: Either move this chunk of code after you have calculated the image size, so that your code becomes:

DWORD dwBytes = ((DWORD) w \* Bpp) / 32;

if(((DWORD) w \* Bpp) % 32) {
   dwBytes++;
}
dwBytes \*= 4;

unsigned long m\_dwSizeImage = dwBytes \* h; // no compression

void\* pBits = tmpImage.GetBits();
HANDLE hData = ::GlobalAlloc (GMEM\_MOVEABLE, sizeof(BITMAPINFO) + m\_dwSizeImage);
LPVOID pData = (LPVOID) ::GlobalLock (hData);
LPBYTE p\_imagebits;
p\_imagebits  = (LPBYTE)pData + sizeof(BITMAPINFO);


memcpy(pData,&bmInfo,sizeof(BITMAPINFO));
memcpy (p\_imagebits, pBits, m\_dwSizeImage);

Or, just use a solution[^] from Codeguru BTW, it looks like you have calculated the m_dwImageSize incorrectly anyway