Trying to manipulate CStdioFile - C / C++ / MFC Discussion Boards

Re: Potentially silly question about CWinThread

nay14-Dec-01 12:09

14-Dec-01 12:09

"I've not had any luck with this."

What I meant was I did call the function after I set the thread running. I was passing a pointer into the function. But as soon as I step into the function (in the debugger) the pointer is garbage. I thought it could be because the function is in the same object as a thread.

Alvaro Mendez wrote:
It should be OK; you'll just be calling the functions from within the original thread instead of the one just created.

Yeah that's what I thought but I wanted an un biased opinion. Thanks for the reply!

nay

What am I missing here?

clintsinger14-Dec-01 7:25

clintsinger

14-Dec-01 7:25

I have a function that is called be visual basic to draw to a picturebox. What that picturebox has is some video on it and I want to be able to change the colours of the image. I am trying to use CreateDIBSection but I seem to be missing something as I can't change the colors. I know that I have the right DC because I can draw a rectangle on it but I can't seem to get a proper bit set. Here is my code:

void __stdcall OverlayMask(long hWnd, long MaskArray)
{
RECT rc;
LONG lWidth = 0;
LONG lHeight = 0;
BITMAPINFO bmi;
HBITMAP hbmp = NULL;
BYTE* bpDIBits = NULL;

GetClientRect((HWND)hWnd, &rc);

lWidth = rc.right - rc.left;
lHeight = rc.bottom - rc.top;

ZeroMemory(&bmi, sizeof(BITMAPINFO));
bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmi.bmiHeader.biWidth = lWidth;
bmi.bmiHeader.biHeight = lHeight;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 24;
bmi.bmiHeader.biCompression = BI_RGB;
bmi.bmiHeader.biXPelsPerMeter = 72;
bmi.bmiHeader.biYPelsPerMeter = 72;

HDC tmpDC = GetDC((HWND)hWnd);
hbmp = CreateDIBSection(
tmpDC, (LPBITMAPINFO)&bmi, DIB_RGB_COLORS,
(LPVOID*)&bpDIBits,
NULL, 0);

if (hbmp == NULL) AtlTrace("Unable to create DIB Section\n");
if (bpDIBits == NULL) AtlTrace("Unable to create DIBits\n");

HBRUSH hBrush = CreateSolidBrush(RGB(0xFF, 0x0F, 0xF0));
FillRect( tmpDC, &rc, hBrush ); // <- This works fine.

for (int i = 0; i < (lWidth*lHeight/3); i++) //<- This
{
*(bpDIBits++) = 0;
*(bpDIBits++);
*(bpDIBits++) = 0x66;
} // <- doesn't

AtlTrace("1) OverlayMask: %x %x", hWnd, MaskArray);

GdiFlush();

ReleaseDC((HWND)hWnd, tmpDC);
}

Thanks in advance,
Clint Singer

Re: What am I missing here?

Joaquín M López Muñoz14-Dec-01 10:33

Joaquín M López Muñoz

14-Dec-01 10:33

Well, after creating the DIB section (which I assume you have no problems with) and doing whatever you want with bpDIBits you will have to paint the bitmap by:

creating a DC compatible with tmpDC (use CreateCompatibleDC for this),
selecting the bitmap you've created into this compatible DC with SelectObject(compatibleDC,hbmp),
doing the actual painting to tmpDC with BitBlt(tmpDC,0,0,lWidth,lHeight,compatibleDC,0,0,SRCCOPY)

Also, don't forget to clean everything up (compatibleDC,hbmp...)

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

accessing an ADO recordset pointer from another window

14-Dec-01 7:13

I´m having trouble using "global" ado recordset pointers in a project.
I have a recordset in a +/- fixed window, that I want to used by other windows that are constantly beeing created and destroyed.
I can access the window pointer easily but when i try to access the recordset pointer the program crashes. The weird thing is that i can visualise the pointer in the debug windows correctly. the code is below, what am I dooing wrong?

class CMainFrame : public CFrameWnd{...
public:
_ConnectionPtr pCon;
CWnd *pTrabalhadoresView;
...}

class CDLG_TRABALHADORES_VIEW : public CResizableFormView{...
public:
_RecordsetPtr
pRstTrabalhadoresDados;
...}

void CDLG_TRABALHADORES_VIEW::OnInitialUpdate()
{...
pMain= (CMainFrame *)AfxGetMainWnd();
pRstTrabalhadoresDados.CreateInstance(__uuidof(Recordset));
pRstTrabalhadoresDados->Open("trabalhadoresdados",_variant_t((IDispatch *)pMain->pCon,true),adOpenDynamic,adLockOptimistic,adCmdTableDirect);
...}

void AnotherWindow::OnSomething(){...
CMainFrame* pMain= (CMainFrame *)AfxGetMainWnd();
CDLG_TRABALHADORES_VIEW* pTrabalhadoresView=(CDLG_TRABALHADORES_VIEW*)pMain->pTrabalhadoresView;
_RecordsetPtr pRstTrabalhadoresData=pTrabalhadoresView->pRstTrabalhadoresDados;
/* UNHANDLED EXCEPTION IN TEST.exe: 0xc0000005: Access violation */
...}

Texas

Re: accessing an ADO recordset pointer from another window

Carlos Antollini14-Dec-01 7:28

Carlos Antollini

14-Dec-01 7:28

Texas:
You need to put the recordset, in the MainFrame and to Instance it in the MainFram. Also you can make the same in the CWinApp Class...
You will can access to the recordset from every window, using

<br />
CWinApp::_RecordsetPtr<br />

\

best Regards...
Green Alien | [Alien]

Chau!!! and good weekend!!!

Carlos Antollini.
Sonork ID 100.10529 cantollini

How to find out unwanted DLL in a System?

14-Dec-01 6:38

Hi,
If I want to find unwanted DLL in the system, how should I find it, is there any method available
Kindly reply me

Regards
John

Re: How to find out unwanted DLL in a System?

Alvaro Mendez14-Dec-01 7:16

Alvaro Mendez

14-Dec-01 7:16

Do you know the name of the DLL? If so, then it's just like finding any regular file on the system. FindFirstFile and FindNextFile are the APIs which immediately come to mind for doing that. The CFileFind class is an alternative if you're using MFC. Other than that, I don't know but I'm trying to remember an API call I came across a while back that would search the hard drive for you. If I remember, I'll post it.

Regards,
Alvaro

Trying to manipulate CStdioFile

Stevieslu14-Dec-01 6:37

Stevieslu

14-Dec-01 6:37

I am trying to replace spaces with newlines \n's in a file to create a single column then I can read the file using ReadString to get one value at a time but it doesn't work. It still thinks the file has the original set-up of rows and columns instead of just a single column. Can anyone explain why?

Here is the code...

CString cFilename = lpszPathName;
CStdioFile fDataFile,fDataCol;
CString szValue;
CString szRow;

fDataFile.Open(lpszPathName, CFile::modeRead);

fDataFile.ReadString(szRow);
int nFirst = szRow.Replace(" ","\n");

while(fDataFile.ReadString(szRow))
{
int nCol = szRow.Replace(" ","\n"); }

fDataFile.Close();

fDataCol.Open(lpszPathName, CFile::modeRead);

BOOL b = fDataCol.ReadString(szValue);

if(TRUE == b)
{
m_nRows = atoi(szValue);
}

b = fDataCol.ReadString(szValue);

if(TRUE == b)
{
m_nColumns = atoi(szValue);
}

m_nValues = (m_nRows*m_nColumns);

m_GraphData.SetSize(m_nRows);

int nRowCount;
int nColumnCount;

for (nRowCount = 0; nRowCount

Re: Trying to manipulate CStdioFile

Alvaro Mendez14-Dec-01 7:19

Alvaro Mendez

14-Dec-01 7:19

Without looking at your code I'm going to guess that it's because you need to use \r\n instead of just \n. Try that and see if it makes a difference.

Regards,
Alvaro

implementing powerpoint presentation slide show

Kuniva14-Dec-01 5:37

Kuniva

14-Dec-01 5:37

does anyone know how i can use powerpoint presentation files in my MFC app and make a slide show in full screen with one? (like the slideshow in powerpoint itself). Is there an active-x container for this or something, or is the powerpoint format simple enough to create the slideshow from scratch?

Easiest way?

Thanx

Kuniva

SuperGeek14-Dec-01 5:31

SuperGeek

14-Dec-01 5:31

Hello everyone.

My question and current task is kinda simple. All I need to do is to send an email to the network admin from my MFC application that runs 24/7 on the server box. Sometimes, for unknown reason, the server box freezes and the only possible action(if I solve this problem) is to send an "alert" message to the network admins that "box needs to be rebooted ASAP".

I know that there are lots of COM components(like ASP mail) out there that facilitate email protocols. As well, there is a number of socket API's and classes.

Does anyone know which way is the fastest and easiest for MFC app to send a simple email.

Big thanks in advance.

Kirill

Re: Email

Andrew Peace15-Dec-01 4:14

Andrew Peace

15-Dec-01 4:14

Use ShellExecute with the program set to a mailto link protocol; i.e mailto:admin@company&subject="blah" etc... using &body. Not a very full answer but I've got some VC problems at the moment so can't access documentation.

--
Andrew.

switching Media player active-x control to full screen

Kuniva14-Dec-01 5:13

Kuniva

14-Dec-01 5:13

How do i switch the Windows Media Player active-x control to fullscreen if its declared as m_cPlayer?

m_cPlayer.SetDisplaySize(?)

if so, what value?

Thanka

Kuniva

Converting int to CString

Cam14-Dec-01 4:53

Cam

14-Dec-01 4:53

First, a big "thank you" to everyone who has been helping me. I know I've been asking a lot of stupid questions, but once I get this stuff relearned, I think I'll be fine.

So, here's the next stupid question. I've got an integer, and and I want it in a CString. For example:

//Before
int myint = 123;

//After
CString mystring = "123";

The problem is that when I try to assign it directly, it puts the character with the ASCII value of the int into the string (I think). Anyway, then I looked up itoa in MSDN, and found a solution. But you must pass itoa a character array to store the resulting text in. Anyway, the only way I know to make it work is like this:

char cDay[3] = " ";
_itoa(theTime.GetDay(), cDay, 10);
CString Day = cDay;

Anyway, the basic idea is that I changed it from an int to a char array, and then from a char array to a CString. But I'm sure there's a way to leave out the char array and just do it directly. Thanks again.

~Cam Desautels (BinaryUprising.com)

Re: Converting int to CString

Joaquín M López Muñoz14-Dec-01 4:59

Joaquín M López Muñoz

14-Dec-01 4:59

The following snippet of code is useful for writing numeric values into std::strings:

#include <sstream>
template <typename T> inline std::string tostring(const T& t)
{
  std::ostringstream ostr;
  ostr<<t;
  return ostr.str();
}

It must be trivial to adapt it for MFC CStrings.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Converting int to CString

Cam14-Dec-01 5:09

Cam

14-Dec-01 5:09

Ahh...yes, if I'm going to be doing a lot of conversions like that, a template would be a very good idea. But I don't really understand that code...I don't get what the binary shift does...but isn't there a more direct route?

~Cam Desautels (BinaryUprising.com)

Re: Converting int to CString

Alvaro Mendez14-Dec-01 5:16

Alvaro Mendez

14-Dec-01 5:16

Here's the most direct way, short of writing your own little function to do it:

CString Day;
Day.Format(_T("%d"), theTime.GetDay());

Regards,
Alvaro

Re: Converting int to CString

Cam14-Dec-01 5:48

Cam

14-Dec-01 5:48

Ahhh

, thank you.

~Cam Desautels (BinaryUprising.com)

How to Change the 'Caption' of a CPropertyPage

14-Dec-01 3:39

Hi there,

can somebody tell me how to Change 'Capiton' text of a CPropertyPage at Runtime.

this

m_psp.pszTitle = "Test";

or this

SetWindowText("Test");

dosn't work

Thanks

Claus

Re: How to Change the 'Caption' of a CPropertyPage

Joaquín M López Muñoz14-Dec-01 4:23

Joaquín M López Muñoz

14-Dec-01 4:23

Check MSDN article Q141487:How to Change the Text in the Tabs of a CPropertySheet.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Creating Excel files

14-Dec-01 2:21

Hello all!

Anybody knows how to create Excel (BIFF) files without Excel (directly write to file)?

I find source code only in Pascal Frown | :-(

((
Need C++ ...

Help!!! Smile | :)

))

Dmitry.

How do I create a "Virtual" Device Context?

Jon Hulatt14-Dec-01 2:04

Jon Hulatt

14-Dec-01 2:04

Hi,

I'm trying to write a bitmap conversion program that reads the bits of a bitmap file and writes them to another file in my custom format.

Because the user's bitmap might not be the required size, i want to scale it to cater for this eventuality.

The CDC::StretchBlt function is good for this, I've used it before. But how can I use this function, when i have no device contect to work with? I am not displaying the bitmap to the screen at any point.

How can i create memory device contexts from nowhere, that are suitable for my bitmap manipulation needs?

Thanks

Jon

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

Re: How do I create a "Virtual" Device Context?

Joaquín M López Muñoz14-Dec-01 2:11

Joaquín M López Muñoz

14-Dec-01 2:11

::CreateCompatibleDC(NULL) will do, I guess.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: How do I create a "Virtual" Device Context?

Jon Hulatt14-Dec-01 3:18

Jon Hulatt

14-Dec-01 3:18

Thanks for that info. It kind of works, but my stretchblt doesn't!
see:

CDC srcDC,destDC;

srcDC.CreateCompatibleDC(NULL);
destDC.CreateCompatibleDC(&srcDC);
destDC.SetStretchBltMode(COLORONCOLOR);
srcDC.SelectObject(m_Bitmap);
destDC.StretchBlt(0,0,WALLPAPER_SIZE_X,WALLPAPER_SIZE_Y,&srcDC,0,0,bm.bmWidth,bm.bmHeight, SRCCOPY);

int x,y;
for (y=0; y<WALLPAPER_SIZE_Y;y++)
{
    for (x=0;x<WALLPAPER_SIZE_X;x++)
    {
        m_PreviewPane.p_ImgData[ (WALLPAPER_SIZE_X * y) + x ]=destDC.GetPixel(x,y);
    }
}

OK. Let me explain what's happening here. I create a source device contect as you suggested, and a destination dc compatible with it. I select my source bitmap into the source device context (srcDC). I then try to strechblt, to scale the image to be WALLPAPER_SIZE_X by WALLPAPER_SIZE_Y in size. bm is a BITMAP structure, containing the source bitmap information.

Tracing through this in the debugger, everything seems valid. bm.bmWidth * bmHeight contain correct source size info, etc etc. But the stretchblt function returns 0 (which is a failure). GetLastError returns 0 as well, if i try that.

The nested loops at the bottom read the scaled bitmap into a previously allocated array. destDC.GetPixel always returns (COLORREF) 0xFFFFFFFF. if i change that line to use srcDC.GetPixel, It returns the proper data from my bitmap.

Basically, I have no idea why stretchblt is failing, and no ideas of how to trace through the problem.

Any help greatly appreciated.

Thanks

Jon

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

Re: How do I create a "Virtual" Device Context?

Jon Hulatt14-Dec-01 3:31

Jon Hulatt

14-Dec-01 3:31

I fixed this now by using the CBitmapDC class from this site!

http://www.codeproject.com/bitmap/bitmapdc.asp#xx49439xx

Thanks all

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

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