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WM_PRINT message

The WM_PRINT message is sent to a window to request that it draw itself in the specified device context, most commonly in a printer device context.

A window receives this message through its WindowProc function.

LRESULT CALLBACK WindowProc(
  HWND hwnd, 
  UINT  uMsg, 
  WPARAM wParam, 
  LPARAM lParam     
);

Parameters

wParam

A handle to the device context to draw in.

lParam

The drawing options. This parameter can be one or more of the following values.

Value Meaning
PRF_CHECKVISIBLE
Draws the window only if it is visible.
PRF_CHILDREN
Draws all visible children windows.
PRF_CLIENT
Draws the client area of the window.
PRF_ERASEBKGND
Erases the background before drawing the window.
PRF_NONCLIENT
Draws the nonclient area of the window.
PRF_OWNED
Draws all owned windows.

 

Remarks

The DefWindowProc function processes this message based on which drawing option is specified: if PRF_CHECKVISIBLE is specified and the window is not visible, do nothing, if PRF_NONCLIENT is specified, draw the nonclient area in the specified device context, if PRF_ERASEBKGND is specified, send the window a WM_ERASEBKGND message, if PRF_CLIENT is specified, send the window a WM_PRINTCLIENT message, if PRF_CHILDREN is set, send each visible child window a WM_PRINT message, if PRF_OWNED is set, send each visible owned window a WM_PRINT message.

Requirements

Requirement Value
Minimum supported client
Windows 2000 Professional [desktop apps only]
Minimum supported server
Windows 2000 Server [desktop apps only]
Header
Winuser.h (include Windows.h)

See also

Painting and Drawing Overview

Painting and Drawing Messages

DefWindowProc

WM_ERASEBKGND

WM_PRINTCLIENT