C / C++ / MFC

Re: Pulling info from other apps

4-Oct-01 8:21

Since you have source for both apps, you may want to use WM_COPYDATA.

RobJones4-Oct-01 11:22

RobJones

4-Oct-01 11:22

Thanks! Right after you posted that I found this http://www.codeproject.com/threads/ipc_wmcopy.asp

Thanks again!

Rob

Grid probs

Jon Hulatt4-Oct-01 7:03

Jon Hulatt

4-Oct-01 7:03

Hi,

I'm a bit clueless here really but I'm sure someone can help me out...

I'm using Chris Maunders MFCGridCtrl class. i want to trap a right click event on a cell. The documentation talks about overriding various "virtual" functions to achieve this.

How do I do this? because not of the grid classes appear in classwizard! I only know how to do this with classwizard.

Thanks

Jon

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Re: Grid probs

Christian Graus4-Oct-01 11:54

Christian Graus

4-Oct-01 11:54

A virtual function means you can derive a class from the MFCGridCtrl class, and 'replace' those functions and things will work properly in terms of calls to the base class. So you need to create a new class, derived from the grid control, and then put in your own versions of those functions by hand.

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

Re: Grid probs

Jon Hulatt4-Oct-01 22:20

Jon Hulatt

4-Oct-01 22:20

Thanks for your help.

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Bitmap and clipboard

#realJSOP4-Oct-01 6:44

4-Oct-01 6:44

I'm capturing a frame from a video stream. The data is being captured (I've verified that) as a 24-bit image. Part of the data being "captured" is the contents of the BITMAPINFOHEADER struct (again, this struct contains viable data).

I want to take this image and store it to the clipboard as a DIB.

Why doesn't this code work?

BITMAPINFO bmi;
memset(&bmi, 0, sizeof(BITMAPINFO));
bmi.bmiHeader = cb.bih; // the cb struct is populated by the capture callback

HDC hMemDC = CreateCompatibleDC(NULL);
HBITMAP hBitmap = CreateDIBitmap(hMemDC, &bmi.bmiHeader, CBM_INIT, cb.pBuffer, &bmi, DIB_RGB_COLORS);

if (OpenClipboard(NULL))
{
   EmptyClipboard();
   if (!SetClipboardData(CF_DIB, hBitmap))
   {
      // show error message
   }
   CloseClipboard();
}

It always says that the hBitmap handle is invalid when I try to call SetClipboardData(). The hBitmap isn't NULL.

C^hris L^osinger4-Oct-01 7:00

4-Oct-01 7:00

try using a real DC (instead of NULL) in your CreateCompatibleDC call. i find that these CreateCompatible things often only work with a real DC.

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

#realJSOP4-Oct-01 7:18

4-Oct-01 7:18

I tried the CreateCompatibleDC method, and the results are the same.

The SDK documentation says that if you pass NULL to CreateCompatibleDC, you get a screen DC. Why isn't that good enough?

Confused | :confused:

C^hris L^osinger4-Oct-01 7:29

4-Oct-01 7:29

that might be true..

i only metion that becaseu i find that doing something like this:

CDC memDC;
memDC.CreateCompatibleDC(pRealDC);
CBitmap memBMP;
memBMP.CreateCompatibleBitmap(memDC, ...);

will often fail (i get a monochrome bitmap or something equally perverse). To make it work I have to use pRealDC in the CreateCompatibleBitmap call. using the 'compatible' DC screws things up.

so, as a rule, i always use a real DC (from GetDC(NULL), or a paint DC or a CClientDC) in these functions.

just a thought.

also, when i copy DIBs to the clipboard, i do it like this:

HGLOBAL CISImage::MakeClipboardDIB()
{
   HGLOBAL hDIB = MakeDIB();
   
   HGLOBAL hCBDIB = NULL;
   if (hDIB)
   {
      DWORD dwSize = GlobalSize(hDIB);
      hCBDIB = GlobalAlloc(GMEM_MOVEABLE | GMEM_DDESHARE, dwSize);
      if (hCBDIB)
      {
         BYTE *pCBDIB = (BYTE *)GlobalLock(hCBDIB);
         memcpy(pCBDIB, (BYTE *)hDIB, dwSize);
         GlobalUnlock(hCBDIB);
      }
      
      GlobalFree(hDIB);
   }
   
   return hCBDIB;
}

...

if (OpenClipboard(AfxGetMainWnd()->m_hWnd))
{
   CISImage img; 

   ...put something in img...etc.

   HGLOBAL hDib = img.MakeClipboardDIB();
   
   HANDLE res = SetClipboardData(CF_DIB, hDib);
   ASSERT(res);

   CloseClipboard();
}

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

#realJSOP4-Oct-01 7:57

4-Oct-01 7:57

I can't find any reference to MakeDIB except for a MSDN sample app, and it requires parameters.

C^hris L^osinger4-Oct-01 7:59

4-Oct-01 7:59

yeah. that's my own function. it just creates a typical BITMAPINFOHEADER and image data DIB. i'm assuming you already have a DIB floating around somewhere.

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

#realJSOP4-Oct-01 8:19

4-Oct-01 8:19

Wel, I have a populated BITMAPINFOHEADER and a shitload of captured bytes... Smile | :)

I've been trying to make a DIB that can be stored to the clipboard. Trouble is, I don't know what I've done right, and what I've done wrong. Smile | :)

Why does something like this have to be so hard in a *graphical* operating system?

C^hris L^osinger4-Oct-01 8:23

4-Oct-01 8:23

sounds like you've got a DIB. have you tried displaying it (with something like StretchDIBits), just to be sure?

// Get source bitmap info
BITMAPINFO *pBMInfo = (LPBITMAPINFO)pDIB ;

// assumes a generic 24bit DIB
LPVOID lpDIBBits = (LPVOID)(pDIB + pBMInfo->bmiHeader.biSize);

// now blast it to the CDC passed in.
// lines returns the number of lines actually displayed
UINT32 lines = StretchDIBits(outHDC,
                     xPos, yPos,
                     outWidth, outHeight,
                     0,0,
                     inWidth,
                     inHeight,
                     lpDIBBits,
                     pBMInfo,
                     DIB_RGB_COLORS,
                     SRCCOPY);

that's the easiest way to tell if your DIB is correct/well-formed.

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

#realJSOP4-Oct-01 8:42

4-Oct-01 8:42

Yup, when I do a StrechDIBits, lines is equal to bmiHeader.biHeight.

C^hris L^osinger4-Oct-01 8:45

4-Oct-01 8:45

hmmm.. have you tried the clipboard code i posted above?

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

#realJSOP4-Oct-01 8:49

4-Oct-01 8:49

not yet - in the process tho...

Tomasz Sowinski4-Oct-01 7:10

Tomasz Sowinski

4-Oct-01 7:10

You can't just pass a dib handle to SetClipboardData - that would be too easy. You have to copy the contents into a global memory block and pass the handle of this memory block to SetClipboardData. DIBLOOK sample may be helpful; have a look at CopyHandle helper.

Tomasz Sowinski -- http://www.shooltz.com

#realJSOP4-Oct-01 7:16

4-Oct-01 7:16

I've already tried the CopyHandle() method, and I get the same results.