The WM_PRINTCLIENT message is sent to a window to request that it draw its client area in the specified device context, most commonly in a printer device context.

Unlike WM_PRINT, WM_PRINTCLIENT is not processed by DefWindowProc. A window should process the WM_PRINTCLIENT message through an application-defined WindowProc function for it to be used properly.

LRESULT CALLBACK WindowProc(
  HWND hwnd,       // handle to window
  UINT uMsg,       // WM_PRINTCLIENT
  WPARAM wParam,   // handle to DC (HDC)
  LPARAM lParam    // drawing options
);

Parameters

wParam

Handle to the device context to draw in.

lParam

Specifies 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

A window can process this message in much the same manner as WM_PAINT, except that BeginPaint and EndPaint need not be called (a device context is provided), and the window should draw its entire client area rather than just the invalid region.

Windows that can be used anywhere in the system, such as controls, should process this message. It is probably worthwhile for other windows to process this message as well because it is relatively easy to implement.

The AnimateWindow function requires that the window being animated implement the WM_PRINTCLIENT message.

Requirements

  Windows NT/2000/XP/Vista: Included in Windows NT 4.0 and later.
  Windows 95/98/Me: Included in Windows 95 and later.
  Header: Declared in Winuser.h; include Windows.h.

See Also

Painting and Drawing Overview, Painting and Drawing Messages, AnimateWindow, BeginPaint, EndPaint, WM_PAINT