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To access the contents, click the chapter and section titles.
Fast Track Visual C++ 6.0 Programming
Listing 10.2 DoublerView.h and DoublerView.cpp // DoublerView.h : interface of the CDoublerView class // ///////////////////////////////////////////////////////////////////////////// #if !defined(AFX_DOUBLERVIEW_H__A45E4A61_A79A_11D1_887F_D42B07C10710__INCLUDED_) #define AFX_DOUBLERVIEW_H__A45E4A61_A79A_11D1_887F_D42B07C10710__INCLUDED_ #if _MSC_VER > 1000 #pragma once #endif // _MSC_VER > 1000 class CDoublerView : public CView { protected: // create from serialization only CDoublerView(); DECLARE_DYNCREATE(CDoublerView) // Attributes public: CDoublerDoc* GetDocument(); // Operations public: // Overrides // ClassWizard generated virtual function overrides //{{AFX_VIRTUAL(CDoublerView) public: virtual void OnDraw(CDC* pDC); // overridden to draw this view virtual BOOL PreCreateWindow(CREATESTRUCT& cs); protected: virtual BOOL OnPreparePrinting(CPrintInfo* pInfo); virtual void OnBeginPrinting(CDC* pDC, CPrintInfo* pInfo); virtual void OnEndPrinting(CDC* pDC, CPrintInfo* pInfo); //}}AFX_VIRTUAL // Implementation public: virtual ~CDoublerView(); #ifdef _DEBUG virtual void AssertValid() const; virtual void Dump(CDumpContext& dc) const; #endif protected: // Generated message map functions protected: //{{AFX_MSG(CDoublerView) afx_msg void OnFileDoublethevalues(); //}}AFX_MSG DECLARE_MESSAGE_MAP() }; #ifndef _DEBUG // debug version in DoublerView.cpp inline CDoublerDoc* CDoublerView::GetDocument() { return (CDoublerDoc*)m_pDocument; } #endif ///////////////////////////////////////////////////////////////////////////// //{{AFX_INSERT_LOCATION}} // Microsoft Visual C++ will insert additional declarations immediately before the previous line. #endif // !defined(AFX_DOUBLERVIEW_H__A45E4A61_A79A_11D1_887F_D42B07C10710__INCLUDED_) // DoublerView.cpp : implementation of the CDoublerView class // #include stdafx.h #include Doubler.h #include DoublerDoc.h #include DoublerView.h #include DoublerDLL.h #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif ///////////////////////////////////////////////////////////////////////////// // CDoublerView IMPLEMENT_DYNCREATE(CDoublerView, CView) BEGIN_MESSAGE_MAP(CDoublerView, CView) //{{AFX_MSG_MAP(CDoublerView) ON_COMMAND(ID_FILE_DOUBLETHEVALUES, OnFileDoublethevalues) //}}AFX_MSG_MAP // Standard printing commands ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint) ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint) ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview) END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // CDoublerView construction/destruction CDoublerView::CDoublerView() { // TODO: add construction code here } CDoublerView::~CDoublerView() { } BOOL CDoublerView::PreCreateWindow(CREATESTRUCT& cs) { // TODO: Modify the Window class or styles here by modifying // the CREATESTRUCT cs return CView::PreCreateWindow(cs); } ///////////////////////////////////////////////////////////////////////////// // CDoublerView drawing void CDoublerView::OnDraw(CDC* pDC) { CDoublerDoc* pDoc = GetDocument(); ASSERT_VALID(pDoc); pDC->TextOut(0, 0, pDoc->text); // TODO: add draw code for native data here } ///////////////////////////////////////////////////////////////////////////// // CDoublerView printing BOOL CDoublerView::OnPreparePrinting(CPrintInfo* pInfo) { // default preparation return DoPreparePrinting(pInfo); } void CDoublerView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/) { // TODO: add extra initialization before printing } void CDoublerView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/) { // TODO: add cleanup after printing } ///////////////////////////////////////////////////////////////////////////// // CDoublerView diagnostics #ifdef _DEBUG void CDoublerView::AssertValid() const { CView::AssertValid(); } void CDoublerView::Dump(CDumpContext& dc) const { CView::Dump(dc); } CDoublerDoc* CDoublerView::GetDocument() // non-debug version is inline { ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CDoublerDoc))); return (CDoublerDoc*)m_pDocument; } #endif //_DEBUG ///////////////////////////////////////////////////////////////////////////// // CDoublerView message handlers void CDoublerView::OnFileDoublethevalues() { // TODO: Add your command handler code here int value1 = 1; int value2 = 2; int result1 = MultiplyByTwo(value1); int result2 = MultiplyByTwo(value2); char FormattedString[80]; wsprintf(FormattedString, 2 times %d is %d, 2 times %d is %d., value1, result1, value2, result2); CDoublerDoc* pDoc = GetDocument(); ASSERT_VALID(pDoc); pDoc->text = FormattedString; Invalidate(); } Now that weve learned the basics of DLLs, we continue by seeing how to share memory between DLLs. Shared Memory in DLLs: The Counter DLLAnother popular use of DLLs is to coordinate data between processes, because you can easily set up shared memory using DLLs. Weve already seen how to set up memory mapped files, and the process with DLLs is similar, but even easier. In this example, Counter, we let the user select a menu itemIncrement counterto increment a counter variable stored in a DLL. Users can open other copies of the Counter program. When they select the Increment counter item, the same counter is incremented, not a new copy of the counter. In this way, we can share the counter variable between several processes. We create a DLL, CounterDLL.dll, to support the counter function IncrementCounter(), and a new MDI application, Counter, to call that function. Lets create the DLL now.
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