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I use official example to simulate this case
You can use double pixelRatio = Get.context.devicePixelRatio;
code snippet
class Controller extends GetxController {
double pixelRatio = Get.context.devicePixelRatio;
int count = 0;
void increment() {
print("pixelRatio $pixelRatio");
count++;
// use update method to update all count variables
update();
}
}
output when click floating action button
I/flutter (19594): pixelRatio 3.5
full code
import 'package:flutter/material.dart';
import 'package:get/get.dart';
void main() {
runApp(GetMaterialApp(
// It is not mandatory to use named routes, but dynamic urls are interesting.
initialRoute: '/home',
defaultTransition: Transition.native,
translations: MyTranslations(),
locale: Locale('pt', 'BR'),
getPages: [
//Simple GetPage
GetPage(name: '/home', page: () => First()),
// GetPage with custom transitions and bindings
GetPage(
name: '/second',
page: () => Second(),
customTransition: SizeTransitions(),
binding: SampleBind(),
),
// GetPage with default transitions
GetPage(
name: '/third',
transition: Transition.cupertino,
page: () => Third(),
),
],
));
}
class MyTranslations extends Translations {
@override
Map<String, Map<String, String>> get keys => {
'en': {
'title': 'Hello World %s',
},
'en_US': {
'title': 'Hello World from US',
},
'pt': {
'title': 'Olá de Portugal',
},
'pt_BR': {
'title': 'Olá do Brasil',
},
};
}
class Controller extends GetxController {
double pixelRatio = Get.context.devicePixelRatio;
int count = 0;
void increment() {
print("pixelRatio $pixelRatio");
count++;
// use update method to update all count variables
update();
}
}
class First extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
leading: IconButton(
icon: Icon(Icons.add),
onPressed: () {
Get.snackbar("Hi", "I'm modern snackbar");
},
),
title: Text("title".trArgs(['John'])),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
GetBuilder<Controller>(
init: Controller(),
// You can initialize your controller here the first time. Don't use init in your other GetBuilders of same controller
builder: (_) => Text(
'clicks: ${_.count}',
)),
RaisedButton(
child: Text('Next Route'),
onPressed: () {
Get.toNamed('/second');
},
),
RaisedButton(
child: Text('Change locale to English'),
onPressed: () {
Get.updateLocale(Locale('en', 'UK'));
},
),
],
),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {
Get.find<Controller>().increment();
}),
);
}
}
class Second extends GetView<ControllerX> {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('second Route'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
GetX<ControllerX>(
// Using bindings you don't need of init: method
// Using Getx you can take controller instance of "builder: (_)"
builder: (_) {
print("count1 rebuild");
return Text('${_.count1}');
},
),
GetX<ControllerX>(
builder: (_) {
print("count2 rebuild");
return Text('${controller.count2}');
},
),
GetX<ControllerX>(builder: (_) {
print("sum rebuild");
return Text('${_.sum}');
}),
GetX<ControllerX>(
builder: (_) => Text('Name: ${controller.user.value.name}'),
),
GetX<ControllerX>(
builder: (_) => Text('Age: ${_.user.value.age}'),
),
RaisedButton(
child: Text("Go to last page"),
onPressed: () {
Get.toNamed('/third', arguments: 'arguments of second');
},
),
RaisedButton(
child: Text("Back page and open snackbar"),
onPressed: () {
Get.back();
Get.snackbar(
'User 123',
'Successfully created',
);
},
),
RaisedButton(
child: Text("Increment"),
onPressed: () {
Get.find<ControllerX>().increment();
},
),
RaisedButton(
child: Text("Increment"),
onPressed: () {
Get.find<ControllerX>().increment2();
},
),
RaisedButton(
child: Text("Update name"),
onPressed: () {
Get.find<ControllerX>().updateUser();
},
),
RaisedButton(
child: Text("Dispose worker"),
onPressed: () {
Get.find<ControllerX>().disposeWorker();
},
),
],
),
),
);
}
}
class Third extends GetView<ControllerX> {
@override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButton: FloatingActionButton(onPressed: () {
controller.incrementList();
}),
appBar: AppBar(
title: Text("Third ${Get.arguments}"),
),
body: Center(
child: Obx(() => ListView.builder(
itemCount: controller.list.length,
itemBuilder: (context, index) {
return Text("${controller.list[index]}");
}))),
);
}
}
class SampleBind extends Bindings {
@override
void dependencies() {
Get.lazyPut<ControllerX>(() => ControllerX());
}
}
class User {
User({this.name = 'Name', this.age = 0});
String name;
int age;
}
class ControllerX extends GetxController {
final count1 = 0.obs;
final count2 = 0.obs;
final list = [56].obs;
final user = User().obs;
updateUser() {
user.update((value) {
value.name = 'Jose';
value.age = 30;
});
}
/// Once the controller has entered memory, onInit will be called.
/// It is preferable to use onInit instead of class constructors or initState method.
/// Use onInit to trigger initial events like API searches, listeners registration
/// or Workers registration.
/// Workers are event handlers, they do not modify the final result,
/// but it allows you to listen to an event and trigger customized actions.
/// Here is an outline of how you can use them:
/// made this if you need cancel you worker
Worker _ever;
@override
onInit() {
/// Called every time the variable $_ is changed
_ever = ever(count1, (_) => print("$_ has been changed (ever)"));
everAll([count1, count2], (_) => print("$_ has been changed (everAll)"));
/// Called first time the variable $_ is changed
once(count1, (_) => print("$_ was changed once (once)"));
/// Anti DDos - Called every time the user stops typing for 1 second, for example.
debounce(count1, (_) => print("debouce$_ (debounce)"),
time: Duration(seconds: 1));
/// Ignore all changes within 1 second.
interval(count1, (_) => print("interval $_ (interval)"),
time: Duration(seconds: 1));
}
int get sum => count1.value + count2.value;
increment() => count1.value++;
increment2() => count2.value++;
disposeWorker() {
_ever.dispose();
// or _ever();
}
incrementList() => list.add(75);
}
class SizeTransitions extends CustomTransition {
@override
Widget buildTransition(
BuildContext context,
Curve curve,
Alignment alignment,
Animation<double> animation,
Animation<double> secondaryAnimation,
Widget child) {
return Align(
alignment: Alignment.center,
child: SizeTransition(
sizeFactor: CurvedAnimation(
parent: animation,
curve: curve,
),
child: child,
),
);
}
}
