
ClientToScreen( )是把窗口坐标转换为屏幕坐标

ScreenToClient( )是把屏幕坐标转换为窗口坐标

屏幕坐标是相对于屏幕左上角的,而窗口坐标是相对于窗口用户区左上角的

VC下,有些函数使用窗口坐标,有些使用屏幕坐标,使用时要分清。



一个窗体分为两部分:系统区和客户区

象标题和菜单之类的是系统区,由系统来控制,客户区就是你的地盘喽!!!

Width, Height 是指整体的,ClientWidth, ClientHeight是指客户区的,两者相减就是

系统区的啦!!!

ClientToScreen是把坐标从当前窗体转化成全屏幕的!!!

ScreenToClient是把屏幕坐标转化成相对当前窗体的坐标!!!!


bool m_bIsLButtonDawn =false;


void CDrawDlg::OnMouseMove(UINT nFlags, CPoint point)



{

// TODO: Add your message handler code here and/or call default

CWnd *pwnd=GetDlgItem(IDC_EDIT1);

CDC *pdc=pwnd->GetDC();

CRect rect;

this->ClientToScreen(&point);

pwnd->ScreenToClient(&point);

pwnd->GetClientRect(&rect);


// HCURSOR hcur=::LoadCursorFromFile("pen.cur");

// SetClassLong(GetSafeHwnd(),GCL_HCURSOR,(LONG)hcur);


// CPen pen(PS_INSIDEFRAME,-1,RGB(255,255,255));

// CPen* olePen=pdc->SelectObject(&pen);

if(rect.PtInRect(point) && m_bIsLButtonDawn )


{


pdc->DPtoLP(&m_fp);

pdc->MoveTo(m_fp);

pdc->DPtoLP(&point);

pdc->LineTo(point);


}

m_fp=point;

// pdc->SelectObject(olePen);

ReleaseDC(pdc);

CDialog::OnMouseMove(nFlags, point);

}


void CDrawDlg::OnLButtonUp(UINT nFlags, CPoint point)



{

m_bIsLButtonDawn =false;

// TODO: Add your message handler code here and/or call default


/**//*

CWnd *pwnd=GetDlgItem(IDC_EDIT1);

CDC *pdc=pwnd->GetDC();

CRect rect;

this->ClientToScreen(&point);

pwnd->ScreenToClient(&point);

pwnd->GetClientRect(&rect);

if(rect.PtInRect(point))

{

pdc->DPtoLP(&m_fp);

pdc->MoveTo(m_fp);

pdc->DPtoLP(&point);

pdc->LineTo(point);

}

ReleaseDC(pdc);*/

CDialog::OnLButtonUp(nFlags, point);

}


void CDrawDlg::OnLButtonDown(UINT nFlags, CPoint point)



{

// TODO: Add your message handler code here and/or call default

CWnd *pwnd=GetDlgItem(IDC_EDIT1);

CDC *pDC=pwnd->GetDC();

CRect rect;

this->ClientToScreen(&point);

pwnd->ScreenToClient(&point);

pwnd->GetClientRect(&rect);

if(rect.PtInRect(point))


{

m_fp.x=point.x;

m_fp.y=point.y;

}

ReleaseDC(pDC);

m_bIsLButtonDawn =true;

CDialog::OnLButtonDown(nFlags, point);

}
