C / C++ / MFC Discussion Boards

S O S4-Dec-02 0:38

4-Dec-02 0:38

Using MFC in a MDI program.
The view has no background, so nothing is painted automatically.
I have this BitBlt on the OnDraw function of a view.

CRect r;<br />
pDC->GetClipBox(&r);<br />
<br />
pDC->BitBlt(r.left, r.top, r.Width(), r.Height(), &pDoc->m_map.m_canvas,<br />
		r.left, r.top, SRCCOPY);

But it doesn't seem to do anything! Not a pixel gets painted.
I tried a FillSolidRect too here and that worked fine.

m_canvas is a DC created with CreateCompatibleDC(NULL)
the rect r seems to be correct and the m_canvas seems to be a valid canvas too.
Oh and the BitBlt returns 1, so it's not failing internally it seems...

Re: BitBlt not working?

Christian Graus4-Dec-02 0:43

Christian Graus

4-Dec-02 0:43

What are the values in r ? Are they within the bounds of the dialog ? Of the canvas ? Try making the last parameter WHITENESS and see what you get. ( You should get a white box ).

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Re: BitBlt not working?

S O S4-Dec-02 5:22

S O S

4-Dec-02 5:22

The m_canvas should be exactly the size of the drawing area
The values in r seem the right ones needed
WHITENESS works fine

I didn't set the size of m_canvas in any way though. Should I have? And if yes, then with what function? I couldn't find anything that would do that

Re: BitBlt not working?

KaЯl4-Dec-02 5:30

KaЯl

4-Dec-02 5:30

Do you have selected a bitmap object in your "m_canvas" memory DC ?

Ohé Partisans, Ouvriers et Paysans
C'est l'alarme!

Le Chant des Partisans

Re: BitBlt not working?

S O S4-Dec-02 5:50

S O S

4-Dec-02 5:50

No. BitBlt doesn't require anything specific to be selected, does it?

Re: BitBlt not working?

KaЯl4-Dec-02 6:03

KaЯl

4-Dec-02 6:03

Ok, it's here probably the problem, there's no data in you document's object. Memory DCs require a bitmap which is the one with stores the graphical info.

When you create your document DC, create also a compatible bitmap (look at CBitmap::CreateCompatibleBitmap), select it in your memory DC, draw on it then BitBlt on your "device" DC.

Here a sample of the mechanic to use, extracted from a drawing method, with
m_SelectionRect = rectangle used to draw "on memory"
DrawMyObject(CDC *pDC): method which actually draws through pDC
dc: the "device" DC

CDC TempMemDC;<br />
CBitmap *pTempBitmap = new CBitmap();<br />
VERIFY(TempMemDC.CreateCompatibleDC(NULL));<br />
VERIFY(pTempBitmap->CreateCompatibleBitmap(&dc, m_SelectionRect.Width(),<br />
m_SelectionRect.Height())); <br />
CBitmap *pOldBitmap = (CBitmap *) TempMemDC.SelectObject(pTempBitmap); <br />
TempMemDC.BitBlt(0, 0, m_SelectionRect.Width(), m_SelectionRect.Height(), BLACKNESS);<br />
// Draw the module in the MemDC<br />
DrawMyObject(&TempMemDC);<br />
dc.BitBlt(0, 0, m_SelectionRect.Width(), m_SelectionRect.Height(), &TempMemDC, 0, 0, SRCCOPY);<br />
// reselect old bitmap<br />
TempMemDC.SelectObject(pOldBitmap);

HTH,

Ohé Partisans, Ouvriers et Paysans
C'est l'alarme!

Le Chant des Partisans

Re: BitBlt not working?

S O S4-Dec-02 7:46

S O S

4-Dec-02 7:46

Thanks, I think I get it now

Re: BitBlt not working?

KaЯl4-Dec-02 13:35

KaЯl

4-Dec-02 13:35

My pleasure if I may help. And welcome on CP Smile | :)

Ohé Partisans, Ouvriers et Paysans
C'est l'alarme!

Le Chant des Partisans

Repaint slider channel

Neha3-Dec-02 23:46

Neha

3-Dec-02 23:46

Hi,
I have written this to repaint the slider channel:

NMCUSTOMDRAW the_struct;
the_struct.hdr.hwndFrom =m_ProgressSlider.m_hWnd;
the_struct.hdr.idFrom = IDC_PROGRESSSLIDER;

the_struct.hdr.code=NM_CUSTOMDRAW;
the_struct.dwDrawStage = CDDS_ITEMPREPAINT;
the_struct.dwItemSpec =TBCD_CHANNEL;
the_struct.hdc =this->GetDC()->m_hDC;
m_ProgressSlider.GetChannelRect(&the_struct.rc);

SendMessage(WM_NOTIFY ,(WPARAM)IDC_PROGRESSSLIDER,(LPARAM)&the_struct);

But slider is not repainted.Can anyone help me..

Regards

Re: Repaint slider channel

KaЯl3-Dec-02 23:58

KaЯl

3-Dec-02 23:58

You probably have to derive your own slider class to do so.
This article[^] may perhaps help

HTH,

Ohé Partisans, Ouvriers et Paysans
C'est l'alarme!

Le Chant des Partisans

Re: MyListCtrl.SetSelectionMark doesn't call OnItemChangedLCtrl(...)

MFC is the Best4-Dec-02 0:15

MFC is the Best

4-Dec-02 0:15

i don´t know, if i understand you right, because my english is not so good.

if you have a listCtrl in MFC, for example: m_ctrlListBox, then you can add a string to the listbox: m_ctrlListBox.AddString("Hi");
if want to to select this entry you can do something like this:

<br />
m_ctrlList.AddString("Hi");<br />
m_ctrlList.SetCurSel(0);<br />
int place=m_ctrlList.GetCurSel();<br />
CString buffer;<br />
m_ctrlList.GetText(place, buffer);<br />

now the buffer includes the first entry of the listbox.

hope i could help you.
mfc

text from edit to list box

xxhimanshu3-Dec-02 23:21

xxhimanshu

3-Dec-02 23:21

i want to enter my edit box text into a list box. how it can be done? can anyone help..

himanshu

Re: text from edit to list box

Michael P Butler3-Dec-02 23:48

Michael P Butler

3-Dec-02 23:48

Are you using MFC?

CString sString = "";<br />
<br />
// Get edit box value<br />
m_edit.GetWindowText(sString);<br />
<br />
// Add edit box value to list control<br />
m_listbox.AddString(sString);

Michael

Fat bottomed girls
You make the rockin' world go round -- Queen

Re: text from edit to list box

Joan M3-Dec-02 23:54

Joan M

3-Dec-02 23:54

Try this:

<br />
CListBox a;<br />
CString b = "";<br />
<br />
yourEditBox.GetWindowText(&b);<br />
a.AddString(b);<br />

Of course you can change the CString and the GetWindowText(...) for a CString variable linked to your editbox... if you want to do it in this way you must call UpdateData();

hope this helps...

Re: text from edit to list box

xxhimanshu4-Dec-02 0:06

xxhimanshu

4-Dec-02 0:06

thanks a lot.. Smile | :)

Problems with data conversion

Gian3-Dec-02 22:57

Gian

3-Dec-02 22:57

Hi,
i've a problem converting data from a format to another. the function

VARIANT SaveToMemory(const VARIANT& Format, const VARIANT& CurSelection);

returns a byte array (text data) casted like a VARIANT. I need to put this array in a CString variable. So I've used this:

COleVariant varBuffer;
COleVariant mode, cur;
mode = (long)5;
cur = (short)TRUE;
varBuffer = m_txctrl.SaveToMemory(mode, cur);
CString m_text = ((CByteArray &)(varBuffer.pbVal)).GetData();

But this will return an empty string. using CString m_text = (varBuffer.pbVal); return me a single byte.

It's wrong my code?

Re: Problems with data conversion

Hans Ruck4-Dec-02 0:50

Hans Ruck

4-Dec-02 0:50

Gian wrote:
returns a byte array (text data) casted like a VARIANT

Where exactly is that byte array? It can't be pbVal because this one is about one single byte... (check MSDN)

rechi

Re: Problems with data conversion

Gian4-Dec-02 3:02

Gian

4-Dec-02 3:02

i've solved calculating the dimension of the OleVariant and using memcpy to copy data in a CByteArray. now works Smile | :)

ODBC, SQL and MFC

MFC is the Best3-Dec-02 22:48

MFC is the Best

3-Dec-02 22:48

hello,

i have an mfc program and an access database. i connected them with odbc.
how can i make the following sql statement in my mfc programm?

select distinct xy from mytable

i want to read out 'xy' from a table 'mytable' and put these CString into a ComboBox:

Now i tried this:

<br />
CMyDatabase db;<br />
db.Open( CRecordset::dynaset,<br />
_T( "Select distinct xy from mytable" ) );<br />
<br />
db.MoveFirst();<br />
while(!db.IsEOF())<br />
{<br />
m_ctrlCombo.AddString(db.m_xy);<br />
db.MoveNext();<br />
}<br />
db.Close();<br />
UpdateData(false);<br />

i get the error, when i want to use this funktion. the error:

error with the call of a data record

what´s wrong????? Unsure | :~

thanks
mfc

Re: ODBC, SQL and MFC

Alexandru Savescu3-Dec-02 23:03

Alexandru Savescu

3-Dec-02 23:03

You need to follow these steps:

1. Open the database (using most likely a DSN, or a connection string).

2. Create a CRecordset object that uses the above open datastring.

3. Open the CRecordset object with a SQL query ("SELECT disintct...")

4. Once the recordset is open, iterate through recordset via MoveNext, MoveFirst etc.

Also, is wise to include everything in a try/catch block and you will most likely catch a pointer to CDBException object.

Best regards,
Alexandru Savescu

P.S. Interested in art? Visit this!

Re: ODBC, SQL and MFC

MFC is the Best3-Dec-02 23:59

MFC is the Best

3-Dec-02 23:59

thanks for reply.

i tried your idea:

	<br />
CMyDatabase db;<br />
db.Open();<br />
CRecordset rs (&db);<br />

but i get an error. must i include something (i included

#include "afxdb.h"
)?

thanks
mfc

Re: ODBC, SQL and MFC

Alexandru Savescu4-Dec-02 1:12

Alexandru Savescu

4-Dec-02 1:12

afxdb is a standard header, so you should use angle brackets:

#include <afxdb.h>

Best regards,
Alexandru Savescu

P.S. Interested in art? Visit this!

Re: ODBC, SQL and MFC

MFC is the Best4-Dec-02 1:20

MFC is the Best

4-Dec-02 1:20

yes, i use angle brackets (< >).....but it does not work.

why? can you help me????

the error is here

<br />
CRecordset rs(&db);<br />

the program has problems with &db

why?
mfc

Re: ODBC, SQL and MFC

Alexandru Savescu4-Dec-02 1:26

Alexandru Savescu

4-Dec-02 1:26

Please tell us what your error is. Apparently afxdb is enough standard to include.

Best regards,
Alexandru Savescu

P.S. Interested in art? Visit this!

Re: ODBC, SQL and MFC

MFC is the Best4-Dec-02 1:34

MFC is the Best

4-Dec-02 1:34

okay...first the code:

<br />
CMyDatabase db;<br />
db.Open();<br />
CRecordset rs (&db);<br />

the error:

'CRecordset::CRecordset':Conversion parameter 1 from 'class CMyDatabase *' in 'class CDatabase *' not possible.

what´s wrong?

thanks
mfc

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