I am designing a login page it overflowed when I click on any text form field it open keyboard and through overflow warning like this see a
Add resizeToAvoidBottomPadding: false, and resizeToAvoidBottomInset: false,
to your Scaffold widget.
Wrap your code with a Container, set the Container's parameters height: MediaQuery.of(context).size.height, and width: MediaQuery.of(context).size.width,. Then wrap your Container with a SingleChildScrollView.