FutureBuilder From Routing Arguments - flutter

Question

I'm working on an application in which the user selects an option from a list on Screen A, then details for that item are retrieved and loaded on Screen B.
I'm confused on how to make this work. FutureBuilder requires that the Future be acquired before the build() function, like in initState(). However, routing arguments are obtained through the BuildContext with ModalRoute.of(myBuildContextHere).settings.arguments, and the BuildContext is only available to the build() function.
Moreover, it seems that Screen B is not actually disposed of when the back button is used to return to Screen A. In my very specific case Screen B displays services provided by a Bluetooth device selected in Screen A. If the selected device is not disconnected when returning to Screen A, it will not appear in the list of available devices. When the device is disconnected, Screen B runs into an error when retrieving details about the characteristics for a disconnected device, though I believe Flutter should've disposed of this Widget when it was popped from the Navigation stack. This issue stems from creating the Future for the FutureBuilder at build-time.
Screen A:
Button(
...
onPressed: () {
Navigator.pushNamed(context, '/screenB', arguments: ScreenBArguments("www.google.com"));
},
...
)
Screen B:
#override
void initState() {
// Oh if only I could access those arguments here!
// setState(() {
// future = _resolveIP(ModalRoute.of(myBuildContext).settings.arguments.url);
// });
}
#override
Widgetbuild build(BuildContext context) {
String URL = ModalRoute.of(context).settings.arguments.url;
return Scaffold(
body: Center(
child: FutureBuilder<String>(
future: _resolveIP(URL), // I can technically spawn a Future here, but now it's created at build-time.
builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
if(ConnectState.done) return Text(snapshot.data);
}
)
)
);
}

Answer 1

The problem is you don't have BuildContext in insitState()
Please try this
#override
void initState() {
SchedulerBinding.instance.addPostFrameCallback((_) {
var result = ModalRoute.of(myBuildContext).settings.arguments.url;
// setState(()=>{});
});
}
#override
Widgetbuild build(BuildContext context) {
String URL = ModalRoute.of(context).settings.arguments.url;
return Scaffold(
body: Center(
child: FutureBuilder<String>(
future: result, // I can technically spawn a Future here, but now it's created at build-time.
builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
if(ConnectState.done) return Text(snapshot.data);
}
)
)
);
}