CWindowDC( CWnd* pWnd );
throw( CResourceException );
Parameters
pWnd
The window whose client area the device-context object will access.
Remarks
Constructs a CWindowDC object that accesses the entire screen area (both client and nonclient) of the CWnd object pointed to by pWnd. The constructor calls the Windows function GetWindowDC.
An exception (of type CResourceException) is thrown if the Windows GetWindowDC call fails. A device context may not be available if Windows has already allocated all of its available device contexts. Your application competes for the five common display contexts available at any given time under Windows.
Example
// Get a dc for a CWnd object pointer.
CWindowDC dc(pWnd);
// Send my private massage.
::SendMessage(pWnd->m_hWnd, WM_MYMESSAGE, 0, 0);