MFC简易计算器实现

因为接触MFC没有多长时间，所以需要写一些小程序来熟悉基本操作，这次写的是一个简易计算器。

外观：

程序下载链接：

MFC简易计算器

写作思路：

这里感谢 逆风微光 博主的博文，基本参照他的思路

http://blog.csdn.net/dpsying/article/details/19047645

由于实现的功能并不多，所以只定义了一个CString变量来接收数据，两个double变量用来储存数据，并且运算符按钮只记录数据和操作，最后的运算在“=”按钮中完成，不过这样做会存在一些Bug。但是简易版计算器并没有考虑那么多=。=

主要代码：

Easy_CalculatorDlg.h

// Easy_CalculatorDlg.h : 头文件//#PRagma once#include "afxwin.h"// CEasy_CalculatorDlg 对话框class CEasy_CalculatorDlg : public CDialogEx{// 构造public:	CEasy_CalculatorDlg(CWnd* pParent = NULL);	// 标准构造函数// 对话框数据#ifdef AFX_DESIGN_TIME	enum { IDD = IDD_EASY_CALCULATOR_DIALOG };#endif	//double变量用来储存数据	double m_Number1;	double m_Number2;	//操作符	int m_Operator;	//储值函数	void SaveValue();	//清空函数	void ClearAll();	//字体变量	CFont m_EditFont;	protected:	virtual void DoDataExchange(CDataExchange* pDX);	// DDX/DDV 支持// 实现protected:	HICON m_hIcon;	// 生成的消息映射函数	virtual BOOL OnInitDialog();	afx_msg void OnSysCommand(UINT nID, LPARAM lParam);	afx_msg void OnPaint();	afx_msg HCURSOR OnQueryDragIcon();	DECLARE_MESSAGE_MAP()public:	CString m_Temp;	CEdit m_Edit;	afx_msg void OnBnClickedButton1();	afx_msg void OnBnClickedButton2();	afx_msg void OnBnClickedButton3();	afx_msg void OnBnClickedButton4();	afx_msg void OnBnClickedButton5();	afx_msg void OnBnClickedButton6();	afx_msg void OnBnClickedButton7();	afx_msg void OnBnClickedButton8();	afx_msg void OnBnClickedButton9();	afx_msg void OnBnClickedButton0();	afx_msg void OnBnClickedButtonPoint();	afx_msg void OnBnClickedButtonAbout();	afx_msg void OnBnClickedButtonPlus();	afx_msg void OnBnClickedButtonSubtract();	afx_msg void OnBnClickedButtonMultiply();	afx_msg void OnBnClickedButtonDivision();	afx_msg void OnBnClickedButtonAc();	afx_msg void OnBnClickedButtonBack();	afx_msg void OnBnClickedButtonEqual();};Easy_CalculatorDlg.cpp
// Easy_CalculatorDlg.cpp : 实现文件//#include "stdafx.h"#include "Easy_Calculator.h"#include "Easy_CalculatorDlg.h"#include "afxdialogex.h"#ifdef _DEBUG#define new DEBUG_NEW#endif// 用于应用程序“关于”菜单项的 CAboutDlg 对话框class CAboutDlg : public CDialogEx{public:	CAboutDlg();// 对话框数据#ifdef AFX_DESIGN_TIME	enum { IDD = IDD_ABOUTBOX };#endif	protected:	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV 支持// 实现protected:	DECLARE_MESSAGE_MAP()};CAboutDlg::CAboutDlg() : CDialogEx(IDD_ABOUTBOX){}void CAboutDlg::DoDataExchange(CDataExchange* pDX){	CDialogEx::DoDataExchange(pDX);}BEGIN_MESSAGE_MAP(CAboutDlg, CDialogEx)END_MESSAGE_MAP()// CEasy_CalculatorDlg 对话框CEasy_CalculatorDlg::CEasy_CalculatorDlg(CWnd* pParent /*=NULL*/)	: CDialogEx(IDD_EASY_CALCULATOR_DIALOG, pParent)	, m_Temp(_T("")){	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);}void CEasy_CalculatorDlg::DoDataExchange(CDataExchange* pDX){	CDialogEx::DoDataExchange(pDX);	DDX_Text(pDX, IDC_EDIT1, m_Temp);	DDX_Control(pDX, IDC_EDIT1, m_Edit);}BEGIN_MESSAGE_MAP(CEasy_CalculatorDlg, CDialogEx)	ON_WM_SYSCOMMAND()	ON_WM_PAINT()	ON_WM_QUERYDRAGICON()	ON_BN_CLICKED(IDC_BUTTON_1, &CEasy_CalculatorDlg::OnBnClickedButton1)	ON_BN_CLICKED(IDC_BUTTON_2, &CEasy_CalculatorDlg::OnBnClickedButton2)	ON_BN_CLICKED(IDC_BUTTON_3, &CEasy_CalculatorDlg::OnBnClickedButton3)	ON_BN_CLICKED(IDC_BUTTON_4, &CEasy_CalculatorDlg::OnBnClickedButton4)	ON_BN_CLICKED(IDC_BUTTON_5, &CEasy_CalculatorDlg::OnBnClickedButton5)	ON_BN_CLICKED(IDC_BUTTON_6, &CEasy_CalculatorDlg::OnBnClickedButton6)	ON_BN_CLICKED(IDC_BUTTON_7, &CEasy_CalculatorDlg::OnBnClickedButton7)	ON_BN_CLICKED(IDC_BUTTON_8, &CEasy_CalculatorDlg::OnBnClickedButton8)	ON_BN_CLICKED(IDC_BUTTON_9, &CEasy_CalculatorDlg::OnBnClickedButton9)	ON_BN_CLICKED(IDC_BUTTON_0, &CEasy_CalculatorDlg::OnBnClickedButton0)	ON_BN_CLICKED(IDC_BUTTON_POINT, &CEasy_CalculatorDlg::OnBnClickedButtonPoint)	ON_BN_CLICKED(IDC_BUTTON_ABOUT, &CEasy_CalculatorDlg::OnBnClickedButtonAbout)	ON_BN_CLICKED(IDC_BUTTON_PLUS, &CEasy_CalculatorDlg::OnBnClickedButtonPlus)	ON_BN_CLICKED(IDC_BUTTON_SUBTRACT, &CEasy_CalculatorDlg::OnBnClickedButtonSubtract)	ON_BN_CLICKED(IDC_BUTTON_MULTIPLY, &CEasy_CalculatorDlg::OnBnClickedButtonMultiply)	ON_BN_CLICKED(IDC_BUTTON_DIVISION, &CEasy_CalculatorDlg::OnBnClickedButtonDivision)	ON_BN_CLICKED(IDC_BUTTON_AC, &CEasy_CalculatorDlg::OnBnClickedButtonAc)	ON_BN_CLICKED(IDC_BUTTON_BACK, &CEasy_CalculatorDlg::OnBnClickedButtonBack)	ON_BN_CLICKED(IDC_BUTTON_EQUAL, &CEasy_CalculatorDlg::OnBnClickedButtonEqual)END_MESSAGE_MAP()// CEasy_CalculatorDlg 消息处理程序BOOL CEasy_CalculatorDlg::OnInitDialog(){	CDialogEx::OnInitDialog();	// 将“关于...”菜单项添加到系统菜单中。	// IDM_ABOUTBOX 必须在系统命令范围内。	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);	ASSERT(IDM_ABOUTBOX < 0xF000);	CMenu* pSysMenu = GetSystemMenu(FALSE);	if (pSysMenu != NULL)	{		BOOL bNameValid;		CString strAboutMenu;		bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);		ASSERT(bNameValid);		if (!strAboutMenu.IsEmpty())		{			pSysMenu->AppendMenu(MF_SEPARATOR);			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);		}	}	// 设置此对话框的图标。  当应用程序主窗口不是对话框时，框架将自动	//  执行此操作	SetIcon(m_hIcon, TRUE);			// 设置大图标	SetIcon(m_hIcon, FALSE);		// 设置小图标	//设置字体	m_EditFont.CreatePointFont(350, "黑体");	m_Edit.SetFont(&m_EditFont);	return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE}void CEasy_CalculatorDlg::OnSysCommand(UINT nID, LPARAM lParam){	if ((nID & 0xFFF0) == IDM_ABOUTBOX)	{		CAboutDlg dlgAbout;		dlgAbout.DoModal();	}	else	{		CDialogEx::OnSysCommand(nID, lParam);	}}// 如果向对话框添加最小化按钮，则需要下面的代码//  来绘制该图标。  对于使用文档/视图模型的 MFC 应用程序，//  这将由框架自动完成。void CEasy_CalculatorDlg::OnPaint(){	if (IsIconic())	{		CPaintDC dc(this); // 用于绘制的设备上下文		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);		// 使图标在工作区矩形中居中		int cxIcon = GetSystemMetrics(SM_CXICON);		int cyIcon = GetSystemMetrics(SM_CYICON);		CRect rect;		GetClientRect(&rect);		int x = (rect.Width() - cxIcon + 1) / 2;		int y = (rect.Height() - cyIcon + 1) / 2;		// 绘制图标		dc.DrawIcon(x, y, m_hIcon);	}	else	{		CDialogEx::OnPaint();	}}//当用户拖动最小化窗口时系统调用此函数取得光标//显示。HCURSOR CEasy_CalculatorDlg::OnQueryDragIcon(){	return static_cast<HCURSOR>(m_hIcon);}void CEasy_CalculatorDlg::ClearAll(){	m_Number1 = 0.0;	m_Number2 = 0.0;	m_Operator = 0;	m_Temp = _T("");}void CEasy_CalculatorDlg::SaveValue(){	UpdateData(TRUE);	m_Number1 = atof(m_Temp);	m_Temp = _T("");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton1(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("1");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton2(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("2");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton3(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("3");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton4(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("4");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton5(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("5");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton6(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("6");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton7(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("7");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton8(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("8");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton9(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("9");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButton0(){	UpdateData(TRUE);	m_Temp = m_Temp + _T("0");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButtonPoint(){	UpdateData(TRUE);	if (-1 == m_Temp.Find('.'))	{		m_Temp = m_Temp + _T(".");	}	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButtonAbout(){	CAboutDlg Dlg;	Dlg.DoModal();}void CEasy_CalculatorDlg::OnBnClickedButtonPlus(){	SaveValue();	m_Operator = 1;}void CEasy_CalculatorDlg::OnBnClickedButtonSubtract(){	SaveValue();	m_Operator = 2;}void CEasy_CalculatorDlg::OnBnClickedButtonMultiply(){	SaveValue();	m_Operator = 3;}void CEasy_CalculatorDlg::OnBnClickedButtonDivision(){	SaveValue();	m_Operator = 4;}void CEasy_CalculatorDlg::OnBnClickedButtonAc(){	m_Number1 = 0.0;	m_Number2 = 0.0;	m_Operator = 0;	m_Temp = _T("");	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButtonBack(){	UpdateData(TRUE);	if (!m_Temp.IsEmpty())	{		m_Temp = m_Temp.Left(m_Temp.GetLength() - 1);	}	UpdateData(FALSE);}void CEasy_CalculatorDlg::OnBnClickedButtonEqual(){	UpdateData(TRUE);	m_Number2 = atof(m_Temp);	double n = 0.0;	switch (m_Operator)	{	case 1:		n = m_Number1 + m_Number2;		break;	case 2:		n = m_Number1 - m_Number2;		break;	case 3:		n = m_Number1 * m_Number2;		break;	case 4:		if (m_Number2 == 0)		{			MessageBox(_T("ERROR"));			ClearAll();		}		else		{			n = m_Number1 / m_Number2;		}		break;	default:		break;	}	m_Temp.Format("%f", n);	m_Temp.TrimRight("0");	m_Temp.TrimRight(".");	UpdateData(FALSE);}背景图片是先引入资源然后用PictureCtrl控件显示，这里注意拖放控件的先后顺序，PictureCtrl控件应该首先被放置，否则会出现图片覆盖按钮的情况，此时需要更改控件顺序。
原博文中最后计算结果会出现16.75000000的情况，当然博主为了将16.000000显示为16采用了一种办法，这里给出一种更简单的处理办法，就是cpp末尾的几行代码。
	m_Temp.Format("%f", n);	m_Temp.TrimRight("0");	m_Temp.TrimRight(".");这样无论是小数还是整数都可以去掉末尾的零。
字体大小改变是在OnInitDialog()函数中添加代码
	//设置字体	m_EditFont.CreatePointFont(350, "黑体");	m_Edit.SetFont(&m_EditFont);这里感谢 守望者在这里 博主的博文。
文章地址：
http://blog.csdn.net/lxw907304340/article/details/46986915
由于简易计算器还存在一些bug，所以后期会考虑写一个功能更加完善的计算器=。=