利用MFC编写计算器

//贴出自己添加的代码，其他代码默认有的
#include "math.h"

// CCounterDlg dialog
CCounterDlg::CCounterDlg(CWnd* pParent /*=NULL*/)
    : CDialog(CCounterDlg::IDD, pParent)
{
    //{{AFX_DATA_INIT(CCounterDlg)
    //初始化
    m_display = 0.0;
    num1 = 0;
    num2 = 0;
    result = 0.0;
    str = "";
    str_flag = FALSE;
    continue_flg = FALSE;
    downDot = FALSE;
    count = 1;

    //}}AFX_DATA_INIT
    // Note that LoadIcon does not require a subsequent DestroyIcon in Win32
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

double CCounterDlg::buttonDownNum(int numSize)
{
    if (!str_flag) //运算符没有被按下，那就是num1
    {
        if (!continue_flg) //按下一次
        {
            num1 = numSize;
            continue_flg =TRUE;
        }
        else
        {
            num1 = num1*pow(10,count) + numSize;
            if (downDot)
            {
                num1 = num1/(pow(10,count));
                count++;
            }
        }
        
        return num1;
    }
    else  //有运算符被按下
    {
        if (!continue_flg) //是否连续按下
        {
            num2 = numSize;
            continue_flg =TRUE;
        }
        else
        {
            num2 = num2*pow(10,count) + numSize;
            if (downDot)
            {
                num2 = num2/(pow(10,count));
                count++;
            }
        }
        
        return num2;
    }
}


void CCounterDlg::OnButton0() 
{
    // TODO: Add your control notification handler code here
    
    m_display = buttonDownNum(0);    
    UpdateData(FALSE);    
}

void CCounterDlg::OnButton1() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(1);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton2() 
{
    // TODO: Add your control notification handler code here
    
    m_display = buttonDownNum(2);
    
    UpdateData(FALSE);
}

void CCounterDlg::OnButton3() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(3);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton4() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(4);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton5() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(5);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton6() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(6);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton7() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(7);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton8() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(8);
    UpdateData(FALSE);
}

void CCounterDlg::OnButton9() 
{
    // TODO: Add your control notification handler code here
    m_display = buttonDownNum(9);
    UpdateData(FALSE);
}

void CCounterDlg::OnButtonDot() //小数点
{
    // TODO: Add your control notification handler code here
    downDot = TRUE; 
//    GetDlgItem(IDC_DISPLAY)->SetWindowText("小数点"); //可以利用该函数在编辑框中显示信息
}

void CCounterDlg::OnButtonAdd() //加
{
    // TODO: Add your control notification handler code here
    str = "+";    
    str_flag = TRUE;
    continue_flg = FALSE;
    downDot = FALSE;
    count = 1;
    UpdateData(FALSE);
}

void CCounterDlg::OnButtonSub()  //减
{
    // TODO: Add your control notification handler code here
    str = "-";    
    str_flag = TRUE;
    continue_flg = FALSE;
    downDot = FALSE;
    count = 1;
    UpdateData(FALSE);
}

void CCounterDlg::OnButtonMult()  //乘
{
    // TODO: Add your control notification handler code here
    str = "*";    
    str_flag = TRUE;
    continue_flg = FALSE;
    downDot = FALSE;
    count = 1;
    UpdateData(FALSE);
}

void CCounterDlg::OnButtonDiv()  //除
{
    // TODO: Add your control notification handler code here
    str = "/";    
    str_flag = TRUE;
    continue_flg = FALSE;
    downDot = FALSE;
    count = 1;
    UpdateData(FALSE);
}

void CCounterDlg::OnButtonEqual() 
{
    // TODO: Add your control notification handler code here
    if(str == "+")
        result = num1 + num2;
    else if(str == "-")
        result = num1 - num2;
    else if(str == "*")
        result = num1 * num2;
    else if(str == "/")
    {
        result = double(num1) / double(num2);
    }

    num1 = result;
    m_display = result;
    str_flag = FALSE;
    continue_flg = FALSE;
    downDot = FALSE;
    count = 1;
    UpdateData(FALSE);
}

void CCounterDlg::OnButtonClear() 
{
    // TODO: Add your control notification handler code here

    num1 = 0;
    num2 = 0;
    m_display = 0;
    continue_flg = FALSE;
    str_flag = FALSE;
    downDot = FALSE;
    count = 1;
    UpdateData(FALSE);
}