孙鑫VC++深入详解:Lesson8 Part1---"逃跑"按钮的实现

1. 用ClassWizard创建一个基于CButton的新类CWeixinBtn,然后利用ClassWizard增加类CWeixinBtn的成员和方法:
    (1)在该类中增加成员: 一个指针CWeixinBtn *m_pBtn,必须是public,否则在类CTestDlg中访问不了.
    (2)在该类中增加一个方法:OnMouseMove(),也就是增加一个鼠标移动到上面的消息响应函数
       在该消息响应函数的实现代码中,隐藏自己,显示别人(m_Btn所指向的那个)


2. CTestDlg中:在将2个按钮(外观一样的)分别增加关联变量m_btn1,m_btn2,变量类型选择CWeixinBtn
     (1)变量m_bt1属于CWeixinBtn类,自动会响应该类中的OnMouseMove
     (2)变量m_bt1的任何响应,实际是其关联的按钮IDC_BUTTON1的响应.
     (3) 在对话框创建完成后(其上的控件按钮也创建OK),它会发送WM_INITDIALOG消息,因此类CTestDlg中有该消息的响应函数OnInitDialog(),在该函数中交换地址,也就是说必须要等到按钮生成后才能获得其地址,也才能交换
        m_btn1.m_pBtn = &m_btn2; //交换按钮的地址
m_btn2.m_pBtn = &m_btn1;

类WeixinBtn.cpp 的实现:

// WeixinBtn.cpp : implementation file//#include "stdafx.h"#include "Test.h"#include "WeixinBtn.h"#ifdef _DEBUG#define new DEBUG_NEW#undef THIS_FILEstatic char THIS_FILE[] = __FILE__;#endif/////////////////////////////////////////////////////////////////////////////// CWeixinBtnCWeixinBtn::CWeixinBtn(){}CWeixinBtn::~CWeixinBtn(){}BEGIN_MESSAGE_MAP(CWeixinBtn, CButton)//{{AFX_MSG_MAP(CWeixinBtn)ON_WM_MOUSEMOVE()//}}AFX_MSG_MAPEND_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////// CWeixinBtn message handlersvoid CWeixinBtn::OnMouseMove(UINT nFlags, CPoint point) {// TODO: Add your message handler code here and/or call defaultthis->ShowWindow(SW_HIDE); //让自己隐藏this->m_pBtn->ShowWindow(SW_SHOW);//让自己的m_pBtn所指向的那个按钮显示CButton::OnMouseMove(nFlags, point);}

CTestDlg.cpp

// TestDlg.cpp : implementation file//#include "stdafx.h"#include "Test.h"#include "TestDlg.h"#ifdef _DEBUG#define new DEBUG_NEW#undef THIS_FILEstatic char THIS_FILE[] = __FILE__;#endif/////////////////////////////////////////////////////////////////////////////// CAboutDlg dialog used for App Aboutclass CAboutDlg : public CDialog{public:CAboutDlg();// Dialog Data//{{AFX_DATA(CAboutDlg)enum { IDD = IDD_ABOUTBOX };//}}AFX_DATA// ClassWizard generated virtual function overrides//{{AFX_VIRTUAL(CAboutDlg)protected:virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support//}}AFX_VIRTUAL// Implementationprotected://{{AFX_MSG(CAboutDlg)//}}AFX_MSGDECLARE_MESSAGE_MAP()};CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD){//{{AFX_DATA_INIT(CAboutDlg)//}}AFX_DATA_INIT}void CAboutDlg::DoDataExchange(CDataExchange* pDX){CDialog::DoDataExchange(pDX);//{{AFX_DATA_MAP(CAboutDlg)//}}AFX_DATA_MAP}BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)//{{AFX_MSG_MAP(CAboutDlg)// No message handlers//}}AFX_MSG_MAPEND_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////// CTestDlg dialogCTestDlg::CTestDlg(CWnd* pParent /*=NULL*/): CDialog(CTestDlg::IDD, pParent){//{{AFX_DATA_INIT(CTestDlg)// NOTE: the ClassWizard will add member initialization here//}}AFX_DATA_INIT// Note that LoadIcon does not require a subsequent DestroyIcon in Win32m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);}void CTestDlg::DoDataExchange(CDataExchange* pDX){CDialog::DoDataExchange(pDX);//{{AFX_DATA_MAP(CTestDlg)DDX_Control(pDX, IDC_BUTTON2, m_btn2);DDX_Control(pDX, IDC_BUTTON1, m_btn1);//}}AFX_DATA_MAP}BEGIN_MESSAGE_MAP(CTestDlg, CDialog)//{{AFX_MSG_MAP(CTestDlg)ON_WM_SYSCOMMAND()ON_WM_PAINT()ON_WM_QUERYDRAGICON()//}}AFX_MSG_MAPEND_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////// CTestDlg message handlersBOOL CTestDlg::OnInitDialog(){CDialog::OnInitDialog();// Add "About..." menu item to system menu.// IDM_ABOUTBOX must be in the system command range.ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);ASSERT(IDM_ABOUTBOX < 0xF000);CMenu* pSysMenu = GetSystemMenu(FALSE);if (pSysMenu != NULL){CString strAboutMenu;strAboutMenu.LoadString(IDS_ABOUTBOX);if (!strAboutMenu.IsEmpty()){pSysMenu->AppendMenu(MF_SEPARATOR);pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);}}// Set the icon for this dialog.  The framework does this automatically//  when the application's main window is not a dialogSetIcon(m_hIcon, TRUE);// Set big iconSetIcon(m_hIcon, FALSE);// Set small icon// TODO: Add extra initialization herem_btn1.m_pBtn = &m_btn2; //交换按钮的地址m_btn2.m_pBtn = &m_btn1;return TRUE;  // return TRUE  unless you set the focus to a control}void CTestDlg::OnSysCommand(UINT nID, LPARAM lParam){if ((nID & 0xFFF0) == IDM_ABOUTBOX){CAboutDlg dlgAbout;dlgAbout.DoModal();}else{CDialog::OnSysCommand(nID, lParam);}}// If you add a minimize button to your dialog, you will need the code below//  to draw the icon.  For MFC applications using the document/view model,//  this is automatically done for you by the framework.void CTestDlg::OnPaint() {if (IsIconic()){CPaintDC dc(this); // device context for paintingSendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);// Center icon in client rectangleint 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;// Draw the icondc.DrawIcon(x, y, m_hIcon);}else{CDialog::OnPaint();}}// The system calls this to obtain the cursor to display while the user drags//  the minimized window.HCURSOR CTestDlg::OnQueryDragIcon(){return (HCURSOR) m_hIcon;}

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