Board index » cppbuilder » THintWindow linking problem

2008-02-03 07:57:10 PM
cppbuilder9
Hi all,
I have made an own class to overwrite the Paint method of the THintWindow
class:
Header file:
class TExtraHintWindow : public THintWindow
{
protected:
void __fastcall Paint(void);
public:
__fastcall TExtraHintWindow(TComponent *Owner);
};
//---------------------------------------------------------------------------
Source file:
__fastcall TExtraHintWindow::TExtraHintWindow(TComponent *Owner)
: THintWindow(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TExtraHintWindow::Paint(void)
{
Canvas->Font->Color = clRed;
THintWindow::Paint();
}
//---------------------------------------------------------------------------
Main form source file:
class THauptformular : public TForm
{
....
private:
TExtraHintWindow *HintFenster;
.....
}
//---------------------------------------------------------------------------
When I compile this and link my program it works fine.
But when I use the new statement in the coding:
__fastcall THauptformular::THauptformular(TComponent *Owner)
: TForm(Owner)
{
HintFenster = new TExtraHintWindow(this);
}
//---------------------------------------------------------------------------
then I get no compiling but linking errors:
[Linking Error] Error: Unsolved external '__fastcall
Controls::THintWindow::NCPaint(void *)' referenced from
C:\DOKUMENTE UND EINSTELLUNGEN\MARIUS\EIGENE DATEIEN\BORLAND
STUDIO-PROJEKTE\MAURO MANAGER 1.5\DEBUG_BUILD\HAUPTFENSTER.OBJ
This file Hauptfenster is my main form source file. I don't understand the
problem here. Has someone an idea?
Regards,
Mauro
 

Hi Mauro
Mauro says:
virtual void __fastcall Paint();
Have You added the TExtraHintWindow unit to Your project ?
Have You at some point had a procedure called NCPaint ?
if so then do a save file and a Build All Project sometimes when
undo is used it is not registered.
In my source files (BCB5) there are no NCPaint there are some WMNCPaint
thats the closest, so the error does look strange.
Kind regards
Asger
 

Hi Asger,
yes, it is virtual, but why should I not write void? Could you explain it to
me?
Hauptfenster.cpp
without success.
don't understand why NCPaint method is mentioned by linker...
Best regards,
Marius
"Asger Joergensen" < XXXX@XXXXX.COM >schrieb im Newsbeitrag

{smallsort}

Sorry I have make a mistake in my answers, it shoul be:
Hauptfenster.cpp
 

I have added the virtual method NCPaint to my class:
class TExtraHintWindow : public THintWindow
{
protected:
virtual void __fastcall Paint();
virtual void __fastcall NCPaint(HDC DC);
public:
__fastcall TExtraHintWindow(TComponent *Owner);
};
This NCPaint method is a method in the class THint window.
Then in my source file I made:
void __fastcall TExtraHintWindow::NCPaint(HDC DC)
{
THintWindow::NCPaint(DC);
}
With this coding the linkg error comes again but when I remove the line
inside the linkg error disappears but in my program sometimes a border is
drawn
around the hint and somethimes not. (Because of the missing NCPaint method
that is responsible for painting the border of the hint element,
mysterious...)
 

Hi Mauro
Mauro says:
but the normal pactice is not to write void, it is only done
in the help files to show that is not parameters.
but I think You must have done that.
Kind regards
Asger
 

Hi Mauro
Take care of all the painting Your self:
TRect Rct = ClientRect;
Canvas->Brush->Color = TheBackgroundColorYouWant;
Canvas->FillRect(Rct);
Canvas->Brush->Color = TheBorderColorYouWant;
int B = YourBorderWidth;
while(B>0)
{
Canvas->FrameRect(Rct);
::InflateRect(&Rct, -1,-1);
--B;
}
::DrawText(Canvas->Handle, Caption.c_str(),Caption.Length(), &Rct,
DT_CENTER | DT_VCENTER // text-drawing flags
);
If You use DT_CALCRECT in the flags You get the window size
needed for the text.
You can see more about the different flags in the DrawText help
This way You can have multiline hinst that are nicely centered.
Kind regards
Asger
 

Hi Asger,
yes, I have also thought about this solution and it works. :-)
Thanks for all hints!
Regards,
Marius
 

"Mauro" < XXXX@XXXXX.COM >wrote in message
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