C++语言 访问对话框中的控件

//创建一个基于对话框的工程,向对话框中添加静态文本,编辑框和组合框控件

enum Symbo {PLUS, SUB, MUL,DIV};
template <class Type>
class CCalc
{
public:
Type Calc(Type &refFirstOpt, Type &refSecOpt, Symbo Opt)
{
switch (Opt)
{
case PLUS:
return refFirstOpt + refSecOpt;
case SUB:
return refFirstOpt - refSecOpt;
case MUL:
return refFirstOpt * refSecOpt;
case DIV:
return refFirstOpt / refSecOpt;
}
}
};

void CCalcDlg::OnCalc()
{
// TODO: Add your control notification handler code here
CString szFirstOpt, szSecOpt, szSymbo, szResult;
m_Symbo.GetWindowText(szSymbo);
if(!szSymbo.IsEmpty())
{
m_FirstOpt.GetWindowText(szFirstOpt);
m_SecOpt.GetWindowText(szSecOpt);

double dbFirst = atof(szFirstOpt.GetBuffer(0));
szFirstOpt.ReleaseBuffer(0);

double dbSec = atof(szSecOpt.GetBuffer(0));
szSecOpt.ReleaseBuffer(0);

Symbo opt;
if(szSymbo == "+")
opt = PLUS;
else if(szSymbo == "-")
opt = SUB;
else if(szSymbo == "*")
opt = MUL;
else if(szSymbo == "/")
opt = DIV;

CCalc<double> CalcObj;
double dbRet = CalcObj.Calc(dbFirst, dbSec, opt);
szResult.Format("%-8.2f", dbRet);
m_Result.SetWindowText(szResult);
szResult.ReleaseBuffer(0);

}

}

//利用控件ID获取控件窗口指针
CString szFirstOpt, szSecOpt, szSymbo, szResult;
CComboBox *pSymbo = (CComboBox*)GetDlgItem(IDC_SYMBO);
pSymbo->GetWindowText(szSymbo);
if(!szSymbo.IsEmpty())
{
CEdit *pFirstOpt = (CEdit*)GetDlgItem(IDC_FIRSTOPT);
pFirstOpt->GetWindowText(szFirstOpt);
CEdit *pSecOpt = (CEdit*)GetDlgItem(IDC_SECOPT);
pSecOpt->GetWindowText(szSecOpt);
double dbFirst = atof(szFirstOpt.GetBuffer(0));
szFirst.ReleaseBuffer(0);
double dbSec = atof(szSecOpt.GetBuffer(0));
szSecOpt.ReleaseBuffer(0));
Symbo opt;
if(szSymbo == "+")
opt = PLUS;
else if(szSymbo == "-")
opt = SUB;
else if(szSymbo == "*")
opt = MUL;
else
opt = DIV;

CCalc<double> CalcObj;
double dbRet = CalcObj.Calc(dbFirst, dbSec, opt);
CEdit *pResult = (CEdit*)GetDlgItem(IDC_RET);
szResult.Format("%-8.2f", dbRet);
pResult->SetWindowText(szResult);
szResult.ReleaseBuffer(0);

}