setState not working anymore if page reloads - flutter

Question

I'm using the package speech_to_text in order to create a voice recognition page.
On the first load of the page, everything seems to be right and the package works perfectly.
If I go back and reopen the voice recognition page, the setState function doesnt' work anymore.
So I worked to put the code in a custom Dialog() of my CustomDialog() class that id builded from the MainPage() class.
I made this in order to use a single Stateful Widget, otherwise I couldn't update the dialog content.
In this way I get the same issue, since in the app there are direct link to the MainPage().
This will rebuild the MainPage() and when I call my CustomDialog(), the setState() is not working anymore.
Here is the code:
void _listen() async {
if (!_isListening) {
bool available = await _speech.initialize(
finalTimeout: const Duration(seconds: 10),
onStatus: (val) {
print('onStatus: $val');
if (val.contains("done")) {
print('>> STATUS DONE');
setState(() {
_isListening = false;
});
}
},
onError: (val) {
print('onError: $val');
},
);
if (available) {
finale = false;
setState(() {
_isListening = true;
stop = false;
finale = false;
});
_speech.listen(
listenMode: stt.ListenMode.confirmation,
onResult: (val) => setState(() {
_text = val.recognizedWords;
if (val.hasConfidenceRating && val.confidence > 0) {
//_confidence = val.confidence;
}
}),
);
}
} else {
setState(() {
_isListening = false;
});
_speech.stop();
}
}
You can see that there is a print value: "STATUS DONE" and this works.
But the setState() after that, is not working.
Any workaround?

Answer 1

The setState method is used to rebuild UI for Stateful widgets. However, when you open a dialog box, you have to keep in mind that it is itself not a stateful widget. You can use the StatefulBuilder widget to overcome this problem:
return StatefulBuilder(
builder: (context, setState) {
return AlertDialog(
title: Text("Title of Dialog"),
content: Text(contentText),
actions: <Widget>[
TextButton(
onPressed: () => Navigator.pop(context),
child: Text("Cancel"),
),
TextButton(
onPressed: () {
setState(() {
contentText = "Changed Content of Dialog";
});
},
child: Text("Change"),
),
],
);
},
);