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