asked on

THOSE ERROR MESSAGE ABOUT?

I JUST USE THE C++ BUILDER 4.0.
MY SOURCE IS:
void __fastcall TForm1::Button1Click(TObject *Sender)
{
TChart::TDBChart *dbc=new TDBChart();

dbc->Assign(DBChart1->Picture->Bitmap);

// TJPEGImage ¤º©wªºÀ£ÁY²v¬O90%
dbc->CompressionQuality=(short)Edit1->Text.ToInt();

dbc->SaveToBitmapFile("Test.bmp");

//±N¦sªºJPG¹ÏÅª¨ìImage2
// JPG->LoadFromFile("test.jpg");

// Image2->Picture->Bitmap->Assign(JPG);

delete dbc;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormClose(TObject *Sender, TCloseAction &Action)
{
if (CheckBox1->Checked)
DeleteFile("Test.bmp");
}

THE ERROR MESSAGE IS:
[C++ Error] TEST.cpp(18): E2451 Undefined symbol 'TDBChart'.
[C++ Error] TEST.cpp(18): E2451 Undefined symbol 'dbc'.
[C++ Error] TEST.cpp(18): E2285 Could not find a match for 'TDBChart::TDBChart()'.
[C++ Error] TEST.cpp(20): E2316 'Picture' is not a member of 'TDBChart'.
[C++ Error] TEST.cpp(23): E2451 Undefined symbol 'Edit1'.
[C++ Error] TEST.cpp(32): E2158 Operand of 'delete' must be non-const pointer.
THOSE ERROR ABOUT WHAT?
THANK YOU!

Zoppo

Hi erichuang,

I found at least one failure:

If TDBChart is declared in namespace of TChart, then
TChart::TDBChart *dbc=new TDBChart();
should be:
TChart::TDBChart *dbc=new TChart::TDBChart();

this should solve the first three and the last error.

the other errors seem to be declaration errors.
Unfortunately I'm not experienced with C++ builder, so I don't know the TDBChart class at all...

ZOPPO

ASKER CERTIFIED SOLUTION

amador

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Zoppo

Hi amador,

some comments:

>if TDBChart is derived for TChart, put TChart:: before.
derived??? I would say TDBChart is declared in namespace TChart, i.e. a 'subclass' of TChart...

>He cant finda the function Picture in TDBChart
From the code I would say 'object Picture' instead of 'function Picture'

>TChart::TDBChart *dbc= (TDBChart *) new TChart::TDBChart();
why use that extra cast (which will not work until you cast to (TCart::TDBChart*)new... ), it's not needed

ZOPPO