VC画线几个常见方法

首先，在VIEW类中增加一个私有的成员变量m_ptOrigin，再增加两个windows的消息响应，一个是WM_LBUTTONDOWN,一个是WM_LBUTTONUP.

1:利用HDC去画线;

2:利用CDC画线;

3:利用CClientDC画线;

4:利用CWindowDC画线;

5:利用Cpen画线;

代码如下(仅包含了WM_LBUTTONDOWN和WM_LBUTTONUP中的代码):

void CBlogView::OnLButtonDown(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
m_ptOrigin=point;
CView::OnLButtonDown(nFlags, point);
}

void CBlogView::OnLButtonUp(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
/* HDC hdc;
hdc=::GetDC(m_hWnd);
MoveToEx(hdc,m_ptOrigin.x,m_ptOrigin.y,NULL);
LineTo(hdc,point.x,point.y);
::ReleaseDC(m_hWnd,hdc);//利用SDK的HDC画线
*/
/* CDC *pDC=GetDC();
pDC->MoveTo(m_ptOrigin);
pDC->LineTo(point);
ReleaseDC(pDC);//利用CDC画线
*/
/* CClientDC dc(this);
dc.MoveTo(m_ptOrigin);
dc.LineTo(point);//利用CClientDC画线
*/
/* CWindowDC dc(GetDesktopWindow());
dc.MoveTo(m_ptOrigin);
dc.LineTo(point);//利用CWindowDC画线。
*/
/* CPen pen(PS_SOLID,1,RGB(123,123,123));
CClientDC dc(this);
CPen *pOldPen=dc.SelectObject(&pen);
dc.MoveTo(m_ptOrigin);
dc.LineTo(point);
dc.SelectObject(pOldPen);//用Cpen去画线
*/
CView::OnLButtonUp(nFlags, point);
}