for example, there is now a task to call the dll, generated by fortran. Due to the long calculation process, in order not to give the user the illusion that the program is dead, it is necessary to give the user real-time feedback on the progress of the calculation. My idea is to first use QT to make a small demo, with a progress bar control, but do not know how to dynamically return this progress information value to associate the progress bar, ask the boss to answer!