Pass data from one screen to another in Flutter with Firestore

Question

I need a gigantic help, I’m having a hard time passing data from one screen to another on Flutter, I’m using Firebase with Firestore on a stream, but I don’t know what I put in Navigator, and how to make the variables for the second screen take the data from the first... Succor!

I need to pass on the data from Productlist to the Productscreen....

Github link if you want to analyze https://github.com/alexandrechoske/BigTudoStore_Flutter

Tetei perform like this but he is not recognizing on Productscreen..

class ProductScreen extends StatefulWidget {

  ProductScreen({this.ref, this.descr}); /* Esse é o creator que vai receber os dados */
  final String ref;
  final String descr;

  @override
  _ProductScreenState createState() => _ProductScreenState();
}

class _ProductScreenState extends State<ProductScreen> {


  @override
  Widget build(BuildContext context) {
    return Container(
      child: Card(
        child: ListTile(
          title: Text(descr)
        ),
      ),
    );
  }
}

and on onTap:

onTap: () {Navigator.push(context, MaterialPageRoute(builder: (context) => ProductScreen(ref: snapshot["ref"], descr: snapshot["descr"])));},

But it accuses an Undefined error name 'descr' on Productscreen.

Tks!!

Answer 1

As you have not put what you have already tried in your question, I will make an example medium above so that you understand.

Modify your Productscreen class as follows:

If you use the Statelesswidget

class ProductScreen statelessWidget{
  ProductScreen({this.nome, this.preco}); /* Esse é o creator que vai receber os dados */
  final String nome;
  final double preco;

  /* Substituir aqui com a sua programação normal*/
  Widget build(BuildCOntext context){
    return Coloumn(
      children: <Widget> [
        Text(nome),
        Text(preco.toString())
      ]
    )
  }
}

If you use the Statefulwidget

class ProductScreen extends StatefulWidget {

  ProductScreen({this.ref, this.descr}); /* Esse é o creator que vai receber os dados */
  final String ref;
  final String descr;

  @override
  _ProductScreenState createState() => _ProductScreenState();
}

class _ProductScreenState extends State<ProductScreen>{
  /* Substituir aqui com a sua programação normal*/
  Widget build(BuildCOntext context){
    return Coloumn(
      children: <Widget> [
        Text(widget.nome),
        Text(widget.preco.toString())
      ]
    )
  }
}

In the onTap() from your list item, do so:

var navigation = await Navigator.push(context, MaterialPageRoute(builder: (context) => ProductScreen(nome: document["nome"], preco: document["preco"])));

Since apparently you are starting with Flutter, I recommend you study some basic language things first!

You can read a little more here Send data to a new screen.