windows_programming_notes.nbk: Home | Index | Next Page: win32 msgs: WM_RENDERALLFORMATS | Previous Page: win32 msgs: WM_PRINT

 win32 msgs: WM_PRINTCLIENT

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.

A window receives this message through its WindowProc function.

    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 or later: Requires Windows NT 4.0 or later.
• Windows 95/98/Me: Requires Windows 95 or later.
• Header: Declared in Winuser.h; include Windows.h.

windows_programming_notes.nbk: Home | Index | Next Page: win32 msgs: WM_RENDERALLFORMATS | Previous Page: win32 msgs: WM_PRINT

Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time