浅谈CDC类中的画线成员方法

CDC：：MoveTo的声明：

CPoint MoveTo(
   int x,
   int y
);
CPoint MoveTo(
   POINT point
);

很显然，MFC重载了MoveTo函数。

CDC::LineTo的声明：
 

BOOL LineTo(
   int x,
   int y
);
BOOL LineTo(
   POINT point
);

下面的例子说明这一点：
lineDemo.h

class CMyApp : public CWinApp {
    virtual BOOL InitInstance();
};

class CMainWindow : public CFrameWnd {
public:
    CMainWindow();
protected:
    afx_msg void OnPaint();
    DECLARE_MESSAGE_MAP()
};

lineDemo.cpp

#include <afxwin.h>
#include "lineDemo.h"

CMyApp myApp;

BOOL CMyApp::InitInstance() {
    m_pMainWnd = new CMainWindow;
    m_pMainWnd->ShowWindow(m_nCmdShow);
    m_pMainWnd->UpdateWindow();
    return TRUE;
}

BEGIN_MESSAGE_MAP(CMainWindow, CFrameWnd)
    ON_WM_PAINT()
END_MESSAGE_MAP()

CMainWindow::CMainWindow() {
    Create(NULL, _T("画线了"));
}

void CMainWindow::OnPaint() {
    CPaintDC dc(this);
    RECT rect;
    GetClientRect(&rect);
    CPoint p(rect.right, rect.bottom);
    dc.LineTo(p);
    p.x = rect.right;
    p.y = 0;
    dc.MoveTo(p);
    dc.LineTo(0, rect.bottom);
    dc.Ellipse(&rect);
}

运行结果：