How to call a future function from a different class?-CodePudding

I have two classes MainScreen and SearchScreen which uses nested function with a boolean value For example, here in MainScreen, I have a function showMap, its return value is obtained from SearchScreen

Future showMap(bool checkValue) async {
        try {
            //do something
        }
        //somewhere in the widgets 
        @override
        Widget build(BuildContext context) {
            super.build(context);
            //
            GestureDetector(
                onTap: () async {
                    await Navigator.push(
                        context,
                        MaterialPageRoute(
                            builder: (context) => SearchScreen(
                                showMapFunction: showMap)));)
            }
        }

NoW in my SearchScreen I have

class SearchScreen extends StatefulWidget {
    final Function showMapFunction;
  

    const SearchScreen({
        this.showMapFunction
    }); //,this.String});

    @override
    _SearchScreenState createState() => _SearchScreenState();
}
///
@override
@mustCallSuper
Widget build(BuildContext context) {
    GestureDetector(
        onTap: () async {
            Navigator.pop(
                //send back data
                // context,
                widget.showMapFunction(true));

        },
        child: Icon(Icons.arrow_back)),
}

This works fine, when I navigate back to MainScreen the function showMap is called, Is there any other way to do this perhaps with provider package or sth? This causes a lot of rebuilds to my widget tree.

CodePudding user response：

What you can do is to await the result of the navigator, like the one used in the Flutter Cookbook.

  void _navigateToSearch(BuildContext context) async {
 
    final result = await Navigator.push(
      context,
       MaterialPageRoute(
                        builder: (context) => SearchScreen())),
    );
  }

And then, when you pop the Search Screen, do the following

 GestureDetector(
  onTap: () async => Navigator.pop(true),
  child: Icon(Icons.arrow_back),
),

I also suggest using WillPopScope.