Form constructor

const Form({Key key, @required Widget child, bool autovalidate: false, WillPopCallback onWillPop, VoidCallback onChanged })

Creates a container for form fields.

The child argument must not be null.

Implementation 

const Form({
  Key key,
  @required this.child,
  this.autovalidate = false,
  this.onWillPop,
  this.onChanged,
}) : assert(child != null),
     super(key: key);