CWindowDC Class
Derived from CDC
.
Syntax
class CWindowDC : public CDC
Members
Public Constructors
Name | Description |
---|---|
CWindowDC::CWindowDC | Constructs a CWindowDC object. |
Protected Data Members
Name | Description |
---|---|
CWindowDC::m_hWnd | The HWND to which this CWindowDC is attached. |
Remarks
Calls the Windows function GetWindowDCat construction time and ReleaseDC at destruction time. This means that a CWindowDC
object accesses the entire screen area of a CWnd (both client and nonclient areas).
For more information on using CWindowDC
, see Device Contexts.
Inheritance Hierarchy
CWindowDC
Requirements
Header: afxwin.h
CWindowDC::CWindowDC
Constructs a CWindowDC
object that accesses the entire screen area (both client and nonclient) of the CWnd
object pointed to by pWnd.
explicit CWindowDC(CWnd* pWnd);
Parameters
pWnd
The window whose client area the device-context object will access.
Remarks
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 message.
::SendMessage(pWnd->m_hWnd, WM_MYMESSAGE, 0, 0);
CWindowDC::m_hWnd
The HWND of the CWnd
pointer is used to construct the CWindowDC
object.
HWND m_hWnd;
Remarks
m_hWnd
is a protected variable of type HWND.
Example
See the example for CWindowDC::CWindowDC.