MFC drawing 1--using different DCs

///using HDC drawing
//
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);
*/
//All window-related operations are encapsulated in the CWnd class
//All drawing-related operations are encapsulated in the CDC class
//using CDC drawing
//
CDC *PDC=CWND::GETDC ();
// The GetDC of the CWnd class is used here directly, and its return value is HDC
Pdc->moveto (M_ptorigin) that is returned using a function of the same name in the cdc*
//sdk;
Pdc->lineto (point);
Cwnd::releasedc (PDC);
*/
//using the CCLIENTDC drawing
/*
CClientDC derives from the CDC, calling GetDC at construction time,
calling ReleaseDC at the time of the destructor. So that we don't have to
Show call GetDC and ReleaseDC.
*/
/*
CCLIENTDC DC (this);
DC. MoveTo (M_ptorigin);
DC. LineTo (point);
*/
//using the CWINDOWDC drawing
/*
also derives from the CDC, constructs the call GETWINDOWDC, and calls ReleaseDC () on the
destructor. The
can access the entire screen area, including the client area and the non-
client area.
*/
/*
CWINDOWDC DC (this);
DC. MoveTo (M_ptorigin);
DC. LineTo (point);
*/
//via GetDesktopWindow get desktop DC
/*
Note: A handle is obtained with the Platform SDK function with the same name, and a function with the same name in CWnd
obtains the CWnd pointer. You can use this function to get the
Desktop window's CWnd pointer so that we can manipulate the desktop.
*/
/*
CWINDOWDC DC (GetDesktopWindow ());
DC. MoveTo (M_ptorigin);
DC. LineTo (point);
*/