DrawText - C / C++ / MFC Discussion Boards

kumar sanghvi14-Dec-09 18:37

14-Dec-09 18:37

Let me be more clear...

Suppose i want to draw segments(rect) on a Dialog and the given coordinates of the segemnt is
0.499567,0.000000,1.000000,0.499369 (these coordinates are independent of the width and height of the Dialog Rect) then how to draw the segment with the given coordinates.....

Re: Rect

Cedric Moonen14-Dec-09 21:04

Cedric Moonen

14-Dec-09 21:04

Do you sometimes read the answers that are given to you ?

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Failed to initialize COM library error

Le@rner14-Dec-09 1:22

Le@rner

14-Dec-09 1:22

Hi all,

I have made a exe using VS-2008.
I am trying to run that exe on another pc which not having VS-2008 inatalled on it (having OS - win xp with sp3), in my exe i have initialised COM using this code.

hres =  CoInitializeEx(0, COINIT_MULTITHREADED); 
    if (FAILED(hres))
    {
        AfxMessageBox(_T("Failed to initialize COM library") );
		return;                  // Program has failed.
    }

But every time i run my exe on this machine it gives "Failed to initialize COM library".

Do i need to install anything extra on this machine...

Or what other problem there might be?

Can anybody help me in this...

Thanks in advance

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Re: Failed to initialize COM library error

CPallini14-Dec-09 1:38

CPallini

14-Dec-09 1:38

You should check better the function return value (make your program reporting it). See the documentation for details [^].
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Re: Failed to initialize COM library error

Durga_Devi14-Dec-09 2:07

Durga_Devi

14-Dec-09 2:07

HI,

For the function CoInitializeEx(), dont check for the returned code.
Because if the COM has been initialized on the calling thread, the return code will be failed i.e S_FALSE.
Just call the CoInitializeEx() and proceed to next.

Re: Failed to initialize COM library error

CPallini14-Dec-09 2:17

CPallini

14-Dec-09 2:17

DurgaDevi_hr wrote:
For the function CoInitializeEx(), dont check for the returned code.
Because if the COM has been initialized on the calling thread, the return code will be failed i.e S_FALSE.

Your point is wrong.

In fact, CoInitializeEx() may return S_FALSE the way you depicted. However FAILED(S_FALSE) evaluates to false.
Smile | :)

Re: Failed to initialize COM library error

transoft14-Dec-09 3:59

transoft

14-Dec-09 3:59

Did you register COM in the new machine?

Using following function always successes for me.

hr = CoCreateInstance( CLSID_App, NULL, CLSCTX_INPROC_SERVER, IID_IUnknown, (void **) &pUnk );

DrawText

kumar sanghvi14-Dec-09 0:32

kumar sanghvi

14-Dec-09 0:32

Hi,
Im trying to draw text on a button which is placed on a Dialog...using the below code in Onpaint

CWnd* pWnd = GetDlgItem(IDC_BUTTON1);
CDC* pDC = pWnd->GetDC();
CRect rect1(3,5,8,10);
pDC->SetTextColor(::GetSysColor(COLOR_HIGHLIGHTTEXT));
pDC->SetBkColor(::GetSysColor(COLOR_HIGHLIGHT));
CBrush brush(RGB(0,0,64));
pDC->SelectObject(&brush);
pDC->DrawText(_T("Example"),&rect1,DT_LEFT|DT_SINGLELINE|DT_VCENTER);
CDialog::OnPaint();

but the above code doesn"t reflect the text...
pls correct me...

Re: DrawText

CPallini14-Dec-09 0:42

CPallini

14-Dec-09 0:42

Yout cannot do that, that way. See, for instance [^].
Smile | :)

Re: DrawText

kumar sanghvi14-Dec-09 0:54

kumar sanghvi

14-Dec-09 0:54

Thanks for ur Reply...but the button control is from Resource not a custom Control....
Is it not possible to draw text on a control which is created from resource..?

Re: DrawText

CPallini14-Dec-09 0:59

CPallini

14-Dec-09 0:59

Usually the button is loaded from resource (where is stored with BS_OWNERDRAW style).
Smile | :)

Re: DrawText

kumar sanghvi14-Dec-09 1:02

kumar sanghvi

14-Dec-09 1:02

If Possible can u explain in more detail..i didn"t get the point..

Re: DrawText

CPallini14-Dec-09 1:29

CPallini

14-Dec-09 1:29

If you're using MFC, this article [^] (from the competitors... Roll eyes | :rolleyes:

) may help.
Smile | :)

DSN Creation through SQLConfigDataSource() funciton

Durga_Devi14-Dec-09 0:17

Durga_Devi

14-Dec-09 0:17

Hi,

The following sample failed to create the DSN,
void main()
{
//As my DB path will change frequently i am using this method.
bool aDSNCreated = false;
char temp[MAX_PATH];
sprintf(temp,"DSN=SAMPLE\0DBQ=D:\\SAMPLE.mdb\0");

aDSNCreated = SQLConfigDataSource(NULL, ODBC_ADD_SYS_DSN, "Microsoft Access Driver (*.mdb)\0", temp);
printf("%d",aDSNCreated );
}

whereas when I execute the below code; it execute successfully.Can anyone help in this why its happening?

void main()
{
bool aDSNCreated = false;

aDSNCreated = SQLConfigDataSource(NULL, ODBC_ADD_SYS_DSN, "Microsoft Access Driver(*.mdb)\0","DSN=SAMPLE\0DBQ=D:\\SAMPLE.mdb\0");
printf("%d",aDSNCreated );
}

Re: DSN Creation through SQLConfigDataSource() funciton

Moak14-Dec-09 0:46

Moak

14-Dec-09 0:46

DurgaDevi_hr wrote:
"Microsoft Access Driver(*.mdb)\0","DSN=SAMPLE\0DBQ=D:\\SAMPLE.mdb\0"

Interesting string format with a double Null-Terminator[^], what were they thinking?

The extra Null-Terminator will cause problems with most C-Runtime string functions.
Have a look at SQLConfigDataSource attributes with variables[^], does this help?

/M

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Re: DSN Creation through SQLConfigDataSource() funciton

Durga_Devi14-Dec-09 1:14

Durga_Devi

14-Dec-09 1:14

Hi Moak,
I tried the logic as specified in the link.

It worked fine. Thanks for that.

But can u tell me, why SQLConfigDataSource() parameter alone is accepting the null terminator string?
Any idea about that? Smile | :)

Re: DSN Creation through SQLConfigDataSource() funciton [modified]

Moak14-Dec-09 1:47

Moak

14-Dec-09 1:47

DurgaDevi_hr wrote:
But can u tell me, why SQLConfigDataSource() parameter alone is accepting the null terminator string?

In a nutshell, the SQLConfigDataSource() uses a strange string format and with a literal text string this is fortunately not a problem (your second example code). But when you use string functions such as sprintf/strcpy/strlen they will stop at the first Null-Terminator. For example "bla\0fasel\0" would be copied only to the the first \0 and becomes "bla\0". You can try it in the debugger. Smile | :)

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modified on Monday, December 14, 2009 7:53 AM

Re: DSN Creation through SQLConfigDataSource() funciton

Durga_Devi14-Dec-09 1:59

Durga_Devi

14-Dec-09 1:59

Tanx for ur reply!!

Re: DSN Creation through SQLConfigDataSource() funciton

David Crow15-Dec-09 3:14

David Crow

15-Dec-09 3:14

DurgaDevi_hr wrote:
The following sample failed to create the DSN,

So then why aren't you calling SQLInstallerError() to find out why?

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Controls are erased when dragging a dialog

m_mun14-Dec-09 0:15

m_mun

14-Dec-09 0:15

Hi all,

I have developed a SDI. It is divided into two parts using a splitter i)simple view ii) another is a dialog(derived from CFormView).
My problem is, whenever i resizing the dialog, all static text and controls are erased and redrawing. How can i stop it?

Thanks to all

Re: Controls are erased when dragging a dialog

Sarath C14-Dec-09 2:30

Sarath C

14-Dec-09 2:30

can you try WS_CLIPCHILDREN[^] style?

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Multiple Documents, CView class - Color change

Paulraj G13-Dec-09 22:36

Paulraj G

13-Dec-09 22:36

Hi...

I am doing a MFC Applicaton.
That is Multiple Document and Base class is CView Class. While i am running the program a white color window is opening. I need to change the white colour window to Block colour window.

Any one have idea, how to convert the window color?

Any help will be appreciated.

Thanks...

G.Paulraj

Re: Multiple Documents, CView class - Color change

Emilio Garavaglia13-Dec-09 22:53

Emilio Garavaglia

13-Dec-09 22:53

Create a "Black Brush" that leave like the window (for example, make it a member of your View class) and retun its handle responding to the WM_ERASEBKGND message.

2 bugs found.
> recompile ...
65534 bugs found.
D'Oh! | :doh:

Re: Multiple Documents, CView class - Color change

Paulraj G13-Dec-09 23:00

Paulraj G

13-Dec-09 23:00

where i have to erase? in OnDraw() method?

G.Paulraj

Re: Multiple Documents, CView class - Color change

Emilio Garavaglia15-Dec-09 5:03

Emilio Garavaglia

15-Dec-09 5:03

Paulraj G wrote:
where i have to erase?

Er ... no. You don't "have to": windows does this before calling WM_PAINT that's handled by MFC via OnDraw().
And does this using the brush that is returned by the WM_ERASEBKGD message, that - by default - is the brush of the WINDOWCLASSEXW structure registered by MFC when creating the very first window ... that is -in turn- the brush returned by GetSysColorBrush(COLOR_WINDOW) that's usually white.

Now, if you have another brush (whatever color or pattern you like) and you trap the WM_ERASEBKGD message (just add the appropriate ON_MESSAGE macro in the message map and define a congruent function) returning your brush, widows will erase with it, and than will call OnDraw().

2 bugs found.
> recompile ...
65534 bugs found.
D'Oh! | :doh:

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