WM_GETMINMAXINFO，ptMaxSize没有任何影响

In handling a WM_GETMINMAXINFO message, I attempt to alter the parameter MINMAXINFO structure by changing the ptMaxSize. It doesn't seem to have any effect. When I receive the WM_SIZE message, I always get the same value, no matter whether I increase or decrease the ptMaxSize in the WM_GETMINMAXINFO.In handling a WM_GETMINMAXINFO message, I attem