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Debugger Exception Notification
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Project DT_EMS.exe raised exception class EInvalidPointer with message 'Invalid pointer operation'. Process stopped. Use Step or Run to continue.
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OK   Help  
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동작은 잘하는데 종료시가 문제입니다.
메인폼에서 스트링그리드 달랑 있는 그리드폼을 쇼모달로 띄우고나서
프로그램 종료시 위와 같은 에러메세지를 랜덤하게(?) 띄웁니다~
급하게 짜느라 부잡스럽운 코드입니다만.. 무엇이 잘못되었을까요?


//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "TGrid.h"
#include "TMain.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TGridForm *GridForm;
//---------------------------------------------------------------------------
__fastcall TGridForm::TGridForm(TComponent* Owner)
    : TForm(Owner)
{
}
//--------------------------------------------------------------------------- 
void __fastcall TGridForm::FormShow(TObject *Sender)
{
    SG->RowCount = 2;
    Download();
}
//---------------------------------------------------------------------------
void __fastcall TGridForm::Download(void)
{                                      
    unsigned char buff[BUFFER_SIZE];         //buffer size [16]
    int start, end, size, cnt = 0;
   
    TFileStream* fs = new TFileStream(MainForm->Edit_Path->Text, fmOpenRead);

    start = MainForm->ListView1->Items->Item[MainForm->ListView1->ItemIndex]->Caption.ToInt()+256;    //256 header size
    fs->Seek(start, soFromBeginning);
    if(MainForm->ListView1->Items->Count-1 == MainForm->ListView1->ItemIndex)
        end = fs->Size;
    else
        end = MainForm->ListView1->Items->Item[MainForm->ListView1->ItemIndex+1]->Caption.ToInt();
    while(true) {
        size = fs->Read(buff, BUFFER_SIZE);
        start += size;
        if(size == 0) break;
        cnt++;
                                                               
        SG->Cells[0][SG->RowCount-1] = IntToStr(cnt); //cnt
        SG->Cells[1][SG->RowCount-1] = IntToStr(buff[0]); //speed
        SG->Cells[2][SG->RowCount-1] = IntToStr((buff[2]<<8)+buff[1]); //rpm
        SG->Cells[3][SG->RowCount-1] = IntToStr(buff[3]); //aux
        SG->Cells[4][SG->RowCount-1] = IntToStr((buff[5]<<8)+buff[4]); //
        SG->Cells[5][SG->RowCount-1] = IntToStr((buff[9]<<24)+(buff[8]<<16)+(buff[7]<<8)+buff[6]); //
        SG->Cells[6][SG->RowCount-1] = IntToStr((buff[13]<<24)+(buff[12]<<16)+(buff[11]<<8)+buff[10]); //
        SG->Cells[7][SG->RowCount-1] = IntToStr((buff[15]<<8)+buff[14]); //

        if(start >= end) break;
        SG->RowCount++;
    }
    delete fs;
}
//---------------------------------------------------------------------------