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 win32 msgs: WM_NCACTIVATE

The WM_NCACTIVATE message is sent to a window when its nonclient area needs to be changed to indicate an active or inactive state.

A window receives this message through its WindowProc function.

    LRESULT CALLBACK WindowProc(
      HWND hwnd,       // handle to window
      UINT uMsg,       // WM_NCACTIVATE
      WPARAM wParam,   // new state (BOOL)
      LPARAM lParam    // not used
    );

Parameters

• wParam Specifies when a title bar or icon needs to be changed to indicate an active or inactive state. If an active title bar or icon is to be drawn, the wParam parameter is TRUE. It is FALSE for an inactive title bar or icon.
• lParam This parameter is not used.

Return Values

When the wParam parameter is FALSE, an application should return TRUE to indicate that the system should proceed with the default processing, or it should return FALSE to prevent the title bar or icon from being deactivated. When wParam is TRUE, the return value is ignored.

Remarks

The DefWindowProc function draws the title bar or icon title in its active colors when the wParam parameter is TRUE and in its inactive colors when wParam is FALSE.

Requirements

  Windows NT/2000 or later: Requires Windows NT 3.1 or later.
  Windows 95/98/Me: Requires Windows 95 or later.
  Header: Declared in Winuser.h; include Windows.h.

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