Flutter-将价值传递给课堂

Question

I'm trying to send a variable from a class to another class in flutter. I don't use buttons so i need to send directly. I have something like this

 final Elements elemento; <-- MODEL 
  final List<Widget> pages = [
    new ParcelasDetailsChartPage(elemento: widget.elemento),
    new Container(
      color: Colors.red,
    ),
    new Container(
      color: Colors.blue,
    )
  ];

In ParcelasDetailsChartPage

  final Elements elemento;

  ParcelasDetailsChartPage({Key key, this.elemento}) : super(key: key);

Return

Only static members can be accessed in initializers.

What is the proper way to do this?

Answer 1

Based on your code: https://gist.github.com/ElHombreSinNombre/4a9dfcbe98a751e87f705748ae1ca3a5

That's because you can't access to widget until the build context is ready.

Change this :

        class ParcelasDetailsPageState extends State<ParcelasDetailsPage> {
          static final GlobalKey<ScaffoldState> scaffoldKey =
              GlobalKey<ScaffoldState>();

          int index = 0;

          final List<Widget> pages = [
            new ParcelasDetailsChartPage(elemento: widget.element),
            new Container(
              color: Colors.red,
            ),
            new Container(
              color: Colors.blue,
            )
          ];

          void initState() {
            super.initState();
            Future.delayed(Duration(seconds: 1)).then((_) => showSnackbar);
          }

To this:

        class ParcelasDetailsPageState extends State<ParcelasDetailsPage> {
          static final GlobalKey<ScaffoldState> scaffoldKey =
              GlobalKey<ScaffoldState>();

          int index = 0;

          List<Widget> pages = List();

          void initState() {
            super.initState();
            pages = [
            new ParcelasDetailsChartPage(elemento: widget.element),
            new Container(
              color: Colors.red,
            ),
            new Container(
              color: Colors.blue,
            )
          ];
            Future.delayed(Duration(seconds: 1)).then((_) => showSnackbar);
          }