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);
}