Re: Bitmap continued

From:

Ed <me@right.her>

Newsgroups:

microsoft.public.vc.mfc

Date:

Mon, 10 Jan 2011 19:08:13 -0500

Message-ID:

<RP2dndUiwYX7ArbQnZ2dnUVZ_jidnZ2d@giganews.com>

I found several errors myself while awaiting your answer as you saw in
my 2nd reply.
Now the bitmap displays BUT it is not within the picture window.
The upper left is within my picture box but the image goes way beyond
the bottom and right of the ShowBmp box.

On 1/10/2011 4:52 PM, Joseph M. Newcomer wrote:

On Mon, 10 Jan 2011 15:05:54 -0500, Ed<me@right.her> wrote:

I am down to two errors during build...

HBITMAP bmp = ::LoadImage(AfxGetInstanceHandle(), filename,
IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_SHARED);

error C2440: 'initializing' : cannot convert from 'void *' to 'struct
HBITMAP__ *'
Conversion from 'void*' to pointer to non-'void' requires an explicit cast
=====================================================================
dc.FillSolidRect(&r,&br);

error C2664: 'void __thiscall CDC::FillSolidRect(const struct tagRECT
*,unsigned long)'
cannot convert parameter 2 from 'class CBrush *' to 'unsigned long'
This conversion requires a reinterpret_cast, a C-style cast or
function-style cast
=====================================================================

****
This is pretty elementary C programming, something you really shouldl have figured out on
your own. A cast is required, as I pointed out in my reply in the earlier thread. I'm
very surprised you couldn't figure out something this simple.
****

I still would like to know where the bitmap selection comes in.

void CShowBmp::OnPaint()
{
   CPaintDC dc(this);

   int filenumber;
// ... formulate filename here, based on the ID
// Example: Files are found in the project's executable directory
   CString t;
   LPTSTR p = t.GetBuffer(MAX_PATH);
   ::GetModuleFileName(NULL, p, MAX_PATH);
   p=_tcsrchr(p, _T('\\'));
   if(p == NULL)
   { /* not possible */
     ASSERT(FALSE);
     t.ReleaseBuffer();
     return;
   } /* not possible */
   ++p;
   *p = _T('\0');
   t.ReleaseBuffer();

   CString filename;
   filename.Format(_T("%s%02d.bmp"), filename, filenumber);

****
My error; this should have said
filename.Format(_T("%s%02d.bmp"), t, filenumber);
I changed the name and didn't catch all the uses.
****

   HBITMAP bmp = ::LoadImage(AfxGetInstanceHandle(), filename,
IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_SHARED);

   // Depending on what I am doing, I might add LR_LOADMAP3DCOLORS or
LR_LOADTRANSPARENT
   if(bmp == NULL)
   { /* failed to load */
     CRect r;
     GetClientRect(&r);

     // Define an error brush. To make it invisible, you might use
     // a solid brush of ::GetSysColor(COLOR_3DFACE)
     // or a hatched brush
     // For a hatched brush, I might set a dark background color

     CBrush br(HS_DIAGCROSS, RGB(0,0,0));
     dc.SetBkColor(RGB(96, 96, 96));

     // This can be recognized as the indication of a failure

     dc.FillSolidRect(&r,&br);

     return;
   } /* failed to load */

   CBitmap bm;
   bm.Attach(bmp);
   BITMAP bmd;
   bm.GetBitmap(&bmd);

   CDC MemDC;
   MemDC.CreateCompatibleDC(&dc);

   int save = MemDC.SaveDC();
   MemDC.SelectObject(&bm);
   // I could use BitBlt or StretchBlt; I;m showing BitBlt below
   dc.BitBlt(0, 0, bmd.bmWidth, bmd.bmHeight,&MemDC, 0,0, SRCCOPY);
   MemDC.RestoreDC(save);
}

Joseph M. Newcomer [MVP]
email: newcomer@flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm