C / C++ / MFC

18-Jul-03 4:21

Hi all,

I have a question about SetFont.

Now I create a class that is derived from CWnd, and use SetFont to set a
font to it. Then I override the Paint function to display the content I
want. The problem happens there, no matter what font I set, when I draw the
text in Paint, it display with the same font, I think it is the system font.

How can I make the SetFont work?

Thanks in advance

C^hris L^osinger18-Jul-03 4:37

C^hris L^osinger

18-Jul-03 4:37

if you are using DrawText or TextOut, you have to use CreateFont/SelectObject . SetFont doesn't do what you think it does.

something like this:

CFont fnt;
fnt.CreateFont(...);
 
CFont *pOldFont = dc.SelectObject(&fnt);
 
dc.TextOut(...);
or
dc.DrawText(...);
 
dc.SelectObject(pOldFont);

-c

CheeseWeasle

Vincent Ye18-Jul-03 4:57

18-Jul-03 4:57

Thank you for your reply.

After reading your comment, I have another question. I have used SetFont to set a font to it. How can I know which font I have set when I want to use it in Paint function. Because my class is used by other people, I have to use a generic way to know which font they set. Actually I have tried another way, I override the SetFont function in my class, and remember the font they said. It worked. But because the SetFont is not a virtual one, when they use a CWnd pointer to call the SetFont function, my SetFont will not be called.

Thanks again.

C^hris L^osinger18-Jul-03 5:40

C^hris L^osinger

18-Jul-03 5:40

vincentye wrote:
How can I know which font I have set when I want to use it in Paint function

have you tried GetFont() ?

-c

CheeseWeasle

Vincent Ye18-Jul-03 5:53

18-Jul-03 5:53

Sure I did.

Some of my code is below:

void CColItem::OnPaint()
{
CPaintDC dc(this); // device context for painting

// TODO: Add your message handler code here
CRect rect;
GetClientRect(rect);

CFont *OldFont = NULL;
OldFont = dc.SelectObject(GetFont());

..............
dc.TextOut(xText, yText, strWindowText);
..............

dc.SelectObject(OldFont);
}

Thanks again

Joel Lucsy18-Jul-03 7:27

Joel Lucsy

18-Jul-03 7:27

The painting code is right. It sounds more like that the code you're using to test it is somehow not passing the right font. Or perhaps you're creating a font that's local (allocated on the stack) and it's going out of scope. SetFont takes a pointer. If that pointer becomes invalid, I'd suspect that the dc.SelectObject( GetFont() ); would fail.
If you're unsure, post the code that calls SetFont and I'll take a look.

Joel Lucsy

Vincent Ye18-Jul-03 7:33

18-Jul-03 7:33

Thank you for your information. However it is not that case.

Below is the answer from MS newsgroup:

"
There is no default implementation of WM_SETFONT and WM_GETFONT. You
need to implement these message handlers to store and return the current
HFONT (or NULL as the case may be), and Invalidate if LPARAM is TRUE.
IIRC, ClassWizard won't help with these, so you'll need to add them
manually using ON_MESSAGE macros in your message-map, and remember that
the prototype is 'LRESULT memberFxn(WPARAM, LPARAM)'. In your WM_PAINT
handler, you will need to SelectObject the currently stored HFONT (if
there is one) into your CPaintDC, and SelectObject it back out again
when you're done.
--
Jeff Partch [VC++ MVP]
"

I follow his instruction. It works well.

Anyway, thanks again.

Help: How to set background bitmap for Rebar?

Ryan Binns18-Jul-03 19:23

Ryan Binns

18-Jul-03 19:23

When you call SetFont(), are you doing something like this?

CFont font;
font.CreateFont(...);
SetFont(&font);

If you do this, the font will be destroyed as soon as the CFont object goes out of scope, so the default system font will be returned by GetFont(). Make sure you either detach the font (CFont::Detach()) or use a font object that is a class member.

Hope this helps,

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

bin892218-Jul-03 4:04

bin8922

18-Jul-03 4:04

I am trying to set a bitmap as background for the CRebar control. But it seems it can only display the image as original size. How can I scale the picture according to the size of the rebar. I want the whole bitmap as background.

string to long part 2

si_6918-Jul-03 3:51

si_69

18-Jul-03 3:51

hi all

thakns for your help so far

at the moment im using the following to convert a string to long

CString stud_id = "00123"
long l;
l = atol (stud_id);

which works ok, but it removes the leading zeros off
so im left with l = "123"

when i want l to = "00123"

does ne1 have ne ideas how to solve this

thanks

si

Ian Darling18-Jul-03 4:00

Ian Darling

18-Jul-03 4:00

The long data type doesn't work like that - 00123 and 123 are identical, because they are stored internally as a binary number, instead of the characters that make up the digits. If you go the other way, look at this:

<br />
long l=123;<br />
CString str, str2;<br />
str.Format(_T("%.5d"), l);   // str contains "00123"<br />
str2.Format(_T("%d"), l);    // str2 contains "123"<br />

Note that if you write:

<br />
long l=0123;  // or 00123 for that matter<br />

Then a C/C++ compiler will treat the literal value as base-8 (octal) instead of base-10 (denary).

--
Ian Darling

RChin18-Jul-03 4:07

RChin

18-Jul-03 4:07

si_69 wrote:
which works ok, but it removes the leading zeros off
so im left with l = "123"

Leading zeros on a number has no significance to the value itself.
123, represented as a number implies an infinite number of leading zeros!.

123 == 0123 == 00123 == 000000123

If you, however, need to display your number with leading zeros, then you can either stick with your string representation, or use something like:

<br />
CString strValue;<br />
long nValue = 1234;<br />
<br />
// convert to string.<br />
// if number is less than 6 digits, pad with zeros.<br />
strValue.Format(_T("%.6ld"), nValue);<br />
<br />
// display to screen<br />
std::cout<<(LPCTSTR)strValue<<std::endl;<br />

"..Even my comments have bugs!"

Inspired by Toni78

Mike Nordell19-Jul-03 4:25

Mike Nordell

19-Jul-03 4:25

RChin wrote:
Leading zeros on a number has no significance to the value itself.

Really? Tried e.g. sscanf lately? As any good C or C++ programmer should know, any number (including literals within the program itself) having a leading zero is an octal number.

Now, let's try to rephrase that statement. Smile | :)

RChin20-Jul-03 23:26

RChin

20-Jul-03 23:26

Sorry. Didn't realise I had to take into account all the number bases on the face of the planet as well! I was commenting on the representation of any number by the system.
See Ian Darling's comment above. He probably has made it more clearer.

So let me rephrase that:
With respect to our natural counting system, .....

"..Even my comments have bugs!"

Inspired by Toni78