The framework calls this member for all windows after the user has logged on or off.
This method receives the WM_USERCHANGED notification message, which is described in the Windows SDK. When the user logs on or off, the operating system updates user-specific settings. The system sends this message immediately after updating the settings.
This member function is called by the framework to allow your application to handle a Windows message. The parameters passed to your function reflect the parameters received by the framework when the message was received. If you call the base-class implementation of this function, that implementation will use the parameters originally passed with the message and not the parameters you supply to the function.
This method is supported in Windows Vista and later.
Additional requirements for this method are described in Build Requirements for Windows Vista Common Controls.