How to send text fields data from list to another screen in flutter

First Screen,pass data in Navigator:

Navigator.push(
            context,
            MaterialPageRoute(builder: (context) =>secondscreen('value')),
          );

in Second Screen:

class secondscreen extends StatefulWidget {
  secondscreen(this.uid);  
  final uid;
  @override
  secondscreenstate createState() => secondscreenstate (this.uid);
}

class secondscreenstate extends State<secondscreen> {
 
  var uid; //where uid will carry the value from first screen
  secondscreenstate (this.uid);
.......

}