Flutter SearchDelegate "BACK" button doesn't execute "close()"

Question

I have an appBar with a search button, which when pressed returns a custom DataSearch class that extends SearchDelegate.

When I close the search page (from the device's go back button or from the widget), I need to execute a certain function first. However the function is only executed from the below widget and not when the device's "BACK" button is pressed.

(Image below)

Here's my code:

class DataSearch extends SearchDelegate<String> {
  @override
  List<Widget> buildActions(BuildContext context) {
    // ...
  }

  @override
  Widget buildLeading(BuildContext context) {
    return IconButton(
      icon: Icon(Icons.arrow_back),
      onPressed: () {
        function_I_need_to_execute();
        close(context, null);
      },
    );
  }

  @override
  Widget buildResults(BuildContext context) {
    // ...
  }

  @override
  Widget buildSuggestions(BuildContext context) {
    // ...
  }
}

I've tried this, but no changes:

@override
  void close(BuildContext context, String result) {
    super.close(context, result);
    function_I_need_to_execute();
  }

I'm considering using the WillPopScope widget but I'm not sure where it fits in the delegate.

Image:

Answer 1

Seems this is not possible using the close method.

However you can do this using the .then method on showSearch since showSearch is a Future.

The then method registers callbacks to be called when this future completes.

showSearch(context: context, delegate: SearchDelegate()).then((value) async{
        await doSomething();
});