Excuse me, is similar to the handle (w_aaa) function returns a handle to the window, can according to the handle to the window to return the window instance? Or ask for a change, you could change this pointer instantiated, this here is to point to a pointer to the window, but this is just a pointer, is not a specific instance, also does not get this call the classname window name string, is want to get the window of the specific instance, don't know what I described not clear, thank you,