vc++编写一个绘图程序

下面是一个简单的VC++绘图程序示例，可以绘制直线和圆形：

首先，创建一个MFC应用程序，选择“单文档”和“视图”选项，并在“视图”选项中选择“绘图视图”：

在“绘图视图.h”中添加以下代码：

class CDrawView : public CView
{
protected: // create from serialization only
    CDrawView();
    DECLARE_DYNCREATE(CDrawView)

// Attributes
public:
    CDrawDoc* GetDocument();

// Operations
public:

// Overrides
    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);

// Implementation
public:
    virtual ~CDrawView();
#ifdef _DEBUG
    virtual void AssertValid() const;
    virtual void Dump(CDumpContext& dc) const;
#endif

protected:
    DECLARE_MESSAGE_MAP()
};

在“绘图视图.cpp”中添加以下代码：

#include "stdafx.h"
#include "Draw.h"
#include "DrawDoc.h"
#include "DrawView.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

// CDrawView

IMPLEMENT_DYNCREATE(CDrawView, CView)

BEGIN_MESSAGE_MAP(CDrawView, CView)
END_MESSAGE_MAP()

// CDrawView construction/destruction

CDrawView::CDrawView()
{
    // TODO: add construction code here

}

CDrawView::~CDrawView()
{
}

BOOL CDrawView::PreCreateWindow(CREATESTRUCT& cs)
{
    // TODO: Modify the Window class or styles here by modifying
    //  the CREATESTRUCT cs

    return CView::PreCreateWindow(cs);
}

// CDrawView drawing

void CDrawView::OnDraw(CDC* pDC)
{
    CDrawDoc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);
    if (!pDoc)
        return;

    // TODO: add draw code for native data here
    pDC->Ellipse(100, 100, 200, 200); // draw a circle
    pDC->MoveTo(300, 100); // move to (300, 100)
    pDC->LineTo(400, 200); // draw a line to (400, 200)
}

// CDrawView printing

BOOL CDrawView::OnPreparePrinting(CPrintInfo* pInfo)
{
    // default preparation
    return DoPreparePrinting(pInfo);
}

void CDrawView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
    // TODO: add extra initialization before printing
}

void CDrawView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
    // TODO: add cleanup after printing
}

// CDrawView diagnostics

#ifdef _DEBUG
void CDrawView::AssertValid() const
{
    CView::AssertValid();
}

void CDrawView::Dump(CDumpContext& dc) const
{
    CView::Dump(dc);
}

CDrawDoc* CDrawView::GetDocument() const // non-debug version is inline
{
    ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CDrawDoc)));
    return (CDrawDoc*)m_pDocument;
}
#endif //_DEBUG

编译并运行程序，就可以看到一个包含一个圆形和一条直线的窗口。