The framework calls this member function one time after the affected window enters a moving or sizing modal loop.
This method receives the WM_ENTERSIZEMOVE notification, which is described in the Windows SDK.
A window enters a moving or sizing modal loop when the user clicks the window's title bar or sizing border, or when the window passes the WM_SYSCOMMAND message to the CWnd::DefWindowProc function and the wParam parameter of that message specifies SC_MOVE or SC_SIZE.
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.