vc++如何将客户区存为bmp
以下代码是从杨琦的论文《在vc中将客户区图像保存到bmp文件》得来 （稍作改动）
在view类中添加以下三个函数：
BOOL CTestestView::WriteWindowToDIB(LPTSTR szFile, CWnd *pWnd)
{
CBitmap bitmap;
CWindowDC dc(pWnd);
CDC memDC;
CRect rect;
memDC.CreateCompatibleDC(&dc);
pWnd->GetWindowRect(rect);
bitmap.CreateCompatibleBitmap(&dc,rect.Width(),rect.Height());
CBitmap* pOldBitmap=memDC.SelectObject(&bitmap);
memDC.BitBlt(0,0,rect.Width(),rect.Height(),&dc,0,0,SRCCOPY);
CPalette pal;
if(dc.GetDeviceCaps(RASTERCAPS)&RC_PALETTE)
{
UINT nSize=sizeof(LOGPALETTE)+(sizeof(PALETTEENTRY)*256);
LOGPALETTE* pLP=(LOGPALETTE*)new BYTE[nSize];
pLP->palVersion=0x300;
pLP->palNumEntries=GetSystemPaletteEntries(dc,0,255,pLP->palPalEntry);
pal.CreatePalette(pLP);
delete[] pLP;
}
memDC.SelectObject(pOldBitmap);
HANDLE hDIB=DDBToDIB(bitmap,BI_RGB,&pal);
if(hDIB==NULL)
return FALSE;
WriteDIB(szFile,hDIB);
GlobalFree(hDIB);
return TRUE;
}
HANDLE CTestestView::DDBToDIB(CBitmap &bitmap, DWORD dwCompression, CPalette *pPal)
{
BITMAP bm;
BITMAPINFOHEADER bi;
LPBITMAPINFOHEADER lpbi;
DWORD dwLen;
HANDLE hDIB;
HANDLE handle;
HDC hDC;
HPALETTE hPal;
ASSERT(bitmap.GetSafeHandle());
if(dwCompression==BI_BITFIELDS)
return NULL;
hPal=(HPALETTE)pPal->GetSafeHandle();
if(hPal==NULL)
hPal=(HPALETTE)GetStockObject(DEFAULT_PALETTE);
bitmap.GetObject(sizeof(bm),(LPSTR)&bm);
bi.biSize=sizeof(BITMAPINFOHEADER);
bi.biWidth=bm.bmWidth;
bi.biHeight=bm.bmHeight;
bi.biPlanes=1;
bi.biBitCount=bm.bmPlanes*bm.bmBitsPixel;
bi.biCompression=dwCompression;
bi.biSizeImage=0;
bi.biXPelsPerMeter=0;
bi.biYPelsPerMeter=0;
bi.biClrImportant=0;
bi.biClrUsed=0;
int nColors=(1<<bi.biBitCount);
if(nColors>256)
nColors=0;
dwLen=bi.biSize+nColors*sizeof(RGBQUAD);
hDC=::GetDC(NULL);
hPal=SelectPalette(hDC,hPal,FALSE);
RealizePalette(hDC);
hDIB=GlobalAlloc(GMEM_FIXED,dwLen);
if(!hDIB)
{
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return NULL;
}
lpbi=(LPBITMAPINFOHEADER)hDIB;
*lpbi=bi;
GetDIBits(hDC,(HBITMAP)bitmap.GetSafeHandle(),0L,(DWORD)bi.biHeight,(LPBYTE)NULL,(LPBITMAPINFO)lpbi,(DWORD)DIB_RGB_COLORS);
bi=*lpbi;
if(bi.biSizeImage==0)
{
bi.biSizeImage=((((bi.biWidth*bi.biBitCount)+31)& ~31)/8)*bi.biHeight;
if(dwCompression!=BI_RGB)
bi.biSizeImage=(bi.biSizeImage*3)/2;
}
dwLen+=bi.biSizeImage;
if(handle=GlobalReAlloc(hDIB,dwLen,GMEM_MOVEABLE))
hDIB=handle;
else
{
GlobalFree(hDIB);
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return NULL;
}
lpbi=(LPBITMAPINFOHEADER)hDIB;
BOOL bGotBits=GetDIBits(hDC,(HBITMAP)bitmap.GetSafeHandle(),0L,(DWORD)bi.biHeight,(LPBYTE)lpbi+(bi.biSize+nColors*sizeof(RGBQUAD)),
(LPBITMAPINFO)lpbi,(DWORD)DIB_RGB_COLORS);
if(!bGotBits)
{
GlobalFree(hDIB);
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return NULL;
}
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return hDIB;
}
BOOL CTestestView::WriteDIB(LPTSTR szFile, HANDLE hDIB)
{
BITMAPFILEHEADER hdr;
LPBITMAPINFOHEADER lpbi;
if(!hDIB)
return FALSE;
CFile file;
if(!file.Open(szFile,CFile::modeWrite|CFile::modeCreate))
return FALSE;
lpbi=(LPBITMAPINFOHEADER)hDIB;
int nColors=1<<lpbi->biBitCount;
hdr.bfType=((WORD)('M'<<8)|'B');
hdr.bfSize=::GlobalSize(hDIB)+sizeof(hdr);
hdr.bfReserved1=0;
hdr.bfReserved2=0;
hdr.bfOffBits=(DWORD)(sizeof(hdr)+lpbi->biSize+nColors*sizeof(RGBQUAD));
file.Write(&hdr,sizeof(hdr));
file.Write(lpbi,GlobalSize(hDIB));
return TRUE;
}
void CTestestView::OnFileSave()
{
// TODO: Add your command handler code here
WriteWindowToDIB("D:\\My.bmp",this);
}
