How build method works how it rebuild itself?

1 Answer. The reason why StatefulWidget uses a separate State class and not having build method inside its body is because all fields inside a Widget are immutable , and this includes all its sub-classes.

Flutter is an open-source software development kit which enables smooth and easy cross-platform mobile app development . You can build high quality natively compiled apps for iOS and Android quickly, without having to write the code for the two apps separately. All you need is one codebase for both platforms.

There are six sets, because whenever you run the Flutter app, the setState() calls the build() method and it displays the number 0 on the screen. Next, each time you press the button, it rebuilds the descendant widget trees also. If we quit the app and restarts the app again, it starts with a fresh display of a screen.22 May 2021