Flutter flatter widget.snapshot.data与snapshot.data

我对

widget.snapshot.data[“info”]

和

snapshot.data[“info”]感到困惑。

谁能解释一下这一点。

widget.snapshot.data[“info”]应该在使用StatefulWidget并且snapshot来自StatefulWidget时使用

范例

class ViewDocuments extends StatefulWidget {
  DocumentSnapshot snapshot;

  ViewDocuments(this.snapshot);

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

class _ViewDocumentsState extends State<ViewDocuments> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text("${widget.snapshot.data["info"]}"),
      ),
    );
  }
}

我希望这对你有帮助

class ViewDocuments extends StatelessWidget {
  DocumentSnapshot snapshot;

  ViewDocuments(this.snapshot);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text("${snapshot.data["info"]}"),
      ),
    );
  }
}