Trying to get a dark theme to work on my project app, spent hours making small tweaks to get it to slowly function. Cant get past this error however, I realise the issue is due to the provider not being on the same level, but cant for the life of me find where I need to rectify the issue. If anyone could help would be awesome. This is where the main issue is.
import 'package:flutter/material.dart';
import 'package:location/location.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:provider/provider.dart';
import 'Colours.dart';
import 'darkmode.dart';
import 'homeDrawer.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'customTransitions.dart';
void main() {
runApp(const MaterialApp(
home: MyState()
)
);
}
class MyState extends StatefulWidget {
const MyState({Key? key}) : super(key: key);
@override
_MyStateState createState() => _MyStateState();
}
class _MyStateState extends State<MyState> {
//Runs automatically when called upon
@override
void initState(){
super.initState();
getCurrentMode();
}
//Reads current stored theme from the preference function and stores it in the provider for user consistency
void getCurrentMode() async {
themeProvider.darkMode =
await themeProvider.dModePreference.getTheme();
}
//Initial declaration of map related values and map controller
late GoogleMapController mapController;
final LatLng _center = const LatLng(52.912170, -1.184238); // Sets default starting map location as Clifton Campus
final Location _location = Location();
//Function runs when the map is created
void _onMapCreated(GoogleMapController controller){
mapController = controller;
}
//creates instance of the theme provider from darkmode.dart
dModeProvider themeProvider = dModeProvider();
@override
Widget build(BuildContext context) {
final themeChange = Provider.of<dModeProvider>(context);
return
ChangeNotifierProvider(
create: (_) => dModeProvider(),
child: Consumer<dModeProvider>(
builder:(BuildContext context, value, Widget? child) {
//MaterialApp wraps page and allows theme changes - dark/light mode
return MaterialApp(
theme: Styles.themeData(themeProvider.darkMode, context),
home: Scaffold(
appBar: AppBar(
title: const Text("Campus Navigation"),
// actions: <Widget> [
// Checkbox(
// value: themeChange.darkMode,
// onChanged: (bool? value){
// themeChange.darkMode = value!;
// }
// )
// ],
flexibleSpace: Container(
decoration: const BoxDecoration(
gradient: LinearGradient(
begin: Alignment.bottomRight,
end: Alignment.topLeft,
colors: [secondaryColour, mainColour])
),
),
),
//Sets the background screen to be slightly obscured
drawerScrimColor: black.withOpacity(0.70),
drawer: const Drawer(
child: homeDrawer(),
),
body: Container(
//Establishes the size of the current device screen and uses that as the sizing for the container
height: MediaQuery
.of(context)
.size
.height,
width: MediaQuery
.of(context)
.size
.width,
child: Stack(
children: [
GoogleMap(
initialCameraPosition: CameraPosition(
target: _center,
zoom: 15.0,
),
onMapCreated: _onMapCreated,
//enabling getting 'my' location
myLocationEnabled: true,
//sets map type to normal or topographic, satellite, etc
mapType: MapType.normal
,
),
],
),
),
),
);
}
),
);
}
}
This is the separate classes made for the provider
import 'package:shared_preferences/shared_preferences.dart';
import 'package:my_application_mpd/Colours.dart';
/// This file has the purpose of making all of the relevant code required to implement a setting for dark mode and light mode
/// Utilised and adapted the method outlined here - https://medium.flutterdevs.com/implement-dark-mode-in-flutter-using-provider-158925112bf9
//Class utilising 'SharedPreferences' to store the setting in the memory and keep dark mode on even if app is closed
class dModePref{
static const THEME_STATUS = "THEMESTATUS";
//When dark mode status is changed, saves it
setdMode( bool value) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
prefs.setBool(THEME_STATUS, value);
}
//Returns current dark mode status
Future<bool> getTheme() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
return prefs.getBool(THEME_STATUS) ?? false;
}
}
//Accesses dThemePref in order to check if the preference has changed and act accordingly
class dModeProvider with ChangeNotifier {
dModePref dModePreference = dModePref();
bool _darkMode = false;
bool get darkMode => _darkMode;
//Sets the dark modes value to the parsed value and notifies app of change
set darkMode (bool value){
_darkMode = value;
dModePreference.setdMode(value);
notifyListeners();
}
}
class Styles {
static ThemeData themeData(bool dModeStatus, BuildContext context){
return ThemeData(
//Theme data for both light and dark mode - detects if dark mode is on and changes to dark colours if it is
//All colours stored within Colours.dart
primarySwatch: Colors.blue,
primaryColor: dModeStatus ? mainColourDark : mainColour,
backgroundColor: dModeStatus ? secondaryColourDark : secondaryColour,
indicatorColor: dModeStatus ? indicatorDark : indicatorLight,
hintColor: dModeStatus ? hintDark : hintLight,
highlightColor: dModeStatus ? highlightDark : highlightLight,
hoverColor: dModeStatus ? hoverDark : hoverLight,
focusColor: dModeStatus ? focusDark : focusLight,
disabledColor: Colors.grey,
cardColor: dModeStatus ? cardDark : cardLight,
canvasColor: dModeStatus ? canvasDark : canvasLight,
brightness: dModeStatus ? Brightness.dark : Brightness.light,
buttonTheme: Theme.of(context).buttonTheme.copyWith(colorScheme: dModeStatus ? const ColorScheme.dark() : const ColorScheme.light()),
appBarTheme: const AppBarTheme(elevation: 0.0,
),
);
}
}
CodePudding user response：
It seems to me, that you did not put on Widget tree after ChangeNotifierProvider class which extends ChangeNotifier. Check the docs https://docs.flutter.dev/development/data-and-backend/state-mgmt/simple