Flutter: How to display a snackbar from an appbar action

Question

I'm trying to display a SnackBar after performing an action from the AppBar. The AppBar cannot be built from a builder so it can't access is Scaffold ancestor. I know we can use a GlobalKey object to access the context whenever we want, but I would like to know if there is a solution without using the GlobalKey. I found some github issues and pull-request, but I can't find a solution from them => https://github.com/flutter/flutter/issues/4581 and https://github.com/flutter/flutter/pull/9380

Some more context: I have an Appbar with a PopupMenuButton, which have one item. When the user click on this item I display a dialog which the showDialog method and if the user clicks on "ok" I want to display a SnackBar

Answer 1

You can use the Builder widget

Example:

Scaffold(
  appBar: AppBar(
    actions: <Widget>[
      Builder(
        builder: (BuildContext context) {
          return IconButton(
            icon: const Icon(Icons.message),
            onPressed: () {
              final snackBar = SnackBar(content: Text('Yay! A SnackBar!'));
              Scaffold.of(context).showSnackBar(snackBar);
            },
          );
        },
      ),
    ],
  )
);