Re: save DC as bitmap to file

From:
"AliR \(VC++ MVP\)" <AliR@online.nospam>
Newsgroups:
microsoft.public.vc.mfc
Date:
Tue, 13 Mar 2007 17:22:57 GMT
Message-ID:
<R5BJh.4679$JZ3.2764@newssvr13.news.prodigy.net>
Take a look at CImage.

You can attach the bitmap handle to a CImage object and call it's Save
method.

So create a second DC and a CBitmap select the bitmap into the DC and draw
on that. Then bitblt the content of the DC on to the screen dc (CPaintDC).
Once you did that unselect the bitmap from the DC. call detach on it to the
hbitmap call attach on the CImage and then call Save.

CPaintDC dc(this);
CDC MemDC;
MemDC.CreateCompatibleDC(&dc);
CBitmap Bmp;
Bmp.CreateCompatibleBitmap(&dc,Width,Height);
CBitmap *pOldBitmap = MemDC.SelectObject(&Bmp);

....Draw on MemDC instead of dc.

dc.BitBlt(0,0,Width,Height,&MemDC,0,0,SRCCOPY);

MemDC.SelectObject(pOldBitmap);

CImage Image;
Image.Attach(Bmp.Detach());
Image.Save(...);

AliR.

"Matthias Pospiech" <matthias79@gmx.de> wrote in message
news:et64ch$dud$1@newsserver.rrzn.uni-hannover.de...

I have a derived CStatic class CGraphCtrl which I use to paint 2D Data to
the screen. The same data shall be saved to a file as a bitmap (bmp or
other standard file format)

The OnPaint() function looks like this:

void CGraphCtrl::OnPaint()
{
CPaintDC dc(this); // device context for painting
CRect rc;
GetClientRect(rc);

CMemDC pDC(&dc, &rc);
...
for (int ix=0; ix < m_PixelNumberX; ix++)
{
for (int iy=0; iy < m_PixelNumberY; iy++)
{
...
pDC->FillSolidRect(getX(x),getY(y),getX(x+1)-getX(x),getY(y+1)-getY(y),c);
...
}
}
}

How is this done ?

Matthias

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