先看我写的程序：
#include <vcl.h>
#pragma hdrstop

#include "Calculator.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
#include"math.h"
TFormCalc::TForm
//---------------------------------------------------------------------------
class TFormCalc
prviate:
  double dblResult;
  double dbOperand;
  char chOperator;
  bool boolPointed;
  void Compute();
__fastcall TFormCalc::TFormCalc(TComponent* Owner)
        : TForm(Owner)
{
EditResult->Text="";
dblResult=double(0);
dblOperand=double(0);
chOperator='+';
boolPointed=false;
}
//---------------------------------------------------------------------------
void __fastcall TFormCalc::ButtonZeroClick(TObject *Sender)
{
EditResult->Text=EditResult->Text+AnsiString(0)
}
//---------------------------------------------------------------------------
void __fastcall TFormCalc::ButtonPointClick(TObject *Sender)
{
EditResult->Text=EditResult->Text+AnsiString('.');
}
//---------------------------------------------------------------------------
void __fastcall TFormCalc::ButtonPlusClick(TObject *Sender)
{
dblOperand=EditResult->Text.ToDouble();
Compute();
//SHowMessage(AnsiString(dblResult));
EditResult->Text="";
chOperator='+';
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ButtonjiusClick(TObject *Sender)
{
dblOperand=EditResult->Text.ToDouble();
Compute();
EditResult->Text="";
chOperator='-';
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ButtonchusClick(TObject *Sender)
{
dblOperand=EditResult->Text.ToDouble();
Compute();
EditResult->Text="";
chOperator='*';
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ButtonDividerClick(TObject *Sender)
{
dblOperand=EditResult->Text.ToDouble();
Compute();
EditResult->Text="";
chOperator='/';        
}
//---------------------------------------------------------------------------
void __fastcall TFormCalc::ButtonOneClick(TObject *Sender)
{
EditResult->Text=EditResult->Text+AnsiString(1);
}
//---------------------------------------------------------------------------
void __fastcall TFormCalc::ButtonTwoClick(TObject *Sender)
{
EditResult->Text=EditResult->Text+AnsiString(2);
}
//---------------------------------------------------------------------------
void __fastcall TFormCale::ButtonThreeClick(TObject *Sender)
{
EditResult->Text=EditResult->Text+AnsiString(3);
}
//---------------------------------------------------------------------------