i am new to flutter also coding.
what i want to do:
to add drawer menu to main.dart, it will return Scaffold for all pages in the menu.
in every page i want to use different Scaffold. (appbar & body)
i created pages, routes, drawer; but i couldn't add drawer to pages and also in the Builder(main.dart), i think i have some mistakes.
main.dart is like this:
import 'package:flutter/material.dart';
import 'package:letter_app/screens/user/postbox.dart';
import 'package:letter_app/screens/user/unread.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
#override
State<StatefulWidget> createState() {
return MyAppState();
}
}
class MyAppState extends State<MyApp> {
int selectedMenuItem = 0;
final pageOptions = [
PostBox(),
Unread(),
];
Widget buildDrawer(BuildContext context) {
return Drawer(
child: ListView(
children: <Widget>[
DrawerHeader(
child: Text('Drawer Header'),
decoration: BoxDecoration(),
),
ListTile(
title: Text('Unread'),
onTap: () {
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => new Unread()));
Navigator.pop(context);
},
),
ListTile(
title: Text('Post Box'),
onTap: () {
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => new PostBox()));
Navigator.pop(context);
},
),
],
),
);
}
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'New App',
theme: ThemeData.dark(),
routes: <String, WidgetBuilder>{
'/screens/user/unread.dart': (BuildContext context) => Unread(),
'/screens/user/postbox.dart': (BuildContext context) => PostBox(),
},
home: Builder(
builder: (context) => Scaffold(
drawer: buildDrawer(context),
body: Container(child: pageOptions[selectedMenuItem]),
),
),
);
}
}
unread.dart is like this:
import 'package:flutter/material.dart';
class Unread extends StatefulWidget {
#override
_UnreadState createState() => _UnreadState();
}
class _UnreadState extends State<Unread> {
#override
Widget build(BuildContext context) {
return Scaffold(
drawer: ,
appBar: AppBar(
title: Text('Welcome to Flutter'),
),
body: Center(
child: Text('Unread'),
),
);
}
}
Just define the buildDrawer widget in a seperate dart file, import the file. Then, just assign it to every Scaffold.
Say I have two pages :-
Tester1.dart
import 'package:flutter/material.dart';
import 'package:gelijk_spel/Testers2.dart';
class Testers1 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Center(
child: IconButton(
icon: Hero(
tag: 'elderimg',
child: Image.asset(
'assets/Images/elder.png', width: 100, height: 100,),
),
onPressed: () {
Navigator.push(context,
MaterialPageRoute(
builder: (context) => Testers2()
)
);
}
),
),
),
);
}
}
and Tester2.dart
import 'package:flutter/material.dart';
class Testers2 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('Screen2'),
),
body: Column(
children: <Widget>[
Text('Placeholder0'),
Hero(
tag: 'elderimg',
child: Image.asset('assets/Images/elder.png',width: 100, height: 100,)
),
Text('Placeholder1'),
],
),
),
);
}
}
I want to be able to transition from Tester1 to Tester2, but instead of having to click on the screen or any events, just sequentially, after some time. How can I achieve this?
One possible approach is to use Timer and a StatefulWidget so you can set up a timer with a trigger that will run your Navigation code as soon as the timer runs out and triggers.
This is the code example:
class Testers1 extends StatefulWidget {
#override
_Testers1State createState() => _Testers1State();
}
class _Testers1State extends State<Testers1> {
Widget build(BuildContext context) {
return Scaffold(
body: Container()
);
}
#override
void initState() {
super.initState();
Timer(Duration(seconds: 10), () {
Navigator.push(
context, MaterialPageRoute(builder: (context) => Testers2()));
});
}
}
class Testers2 extends StatelessWidget {
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Screen2'),
),
body: Column(
children: <Widget>[
Text('Placeholder0'),
Text('Placeholder1'),
],
),
);
}
}
NOTE: Timer is coming from the 'dart:async'
Yes, you have to use Future.delayed() on init() function in first page
Like this(Add this to First page):
Future<void> initState() {
super.initState();
//replace 1000 with your time required
Future.delayed(Duration(milliseconds: 1000), () {
Navigator.push(currentContext,
MaterialPageRoute(builder: (context) => Testers2()));
},
});
}
I want a widget that will sit on top of the entire application. When I have tried to do this with Overlay.of(context).insert the overlay would later disappear after replacing that route. Is there a way I can have a widget on top of my app even if the screen is later popped?
Maybe a more optimal way exists, but as an option this is an example with two pages, local navigator and Overlay.
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
final _navigatorKey = GlobalKey<NavigatorState>();
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: WillPopScope(
onWillPop: () async => !await _navigatorKey.currentState.maybePop(),
child: LayoutBuilder(
builder: (context, constraints) {
WidgetsBinding.instance.addPostFrameCallback((_) => _insertOverlay(context));
return Navigator(
key: _navigatorKey,
onGenerateRoute: (RouteSettings settings) {
switch (settings.name) {
case '/page2':
return MaterialPageRoute(builder: (_) => Page2());
default:
return MaterialPageRoute(builder: (_) => Page1(_navigatorKey));
}
},
);
},
),
),
);
}
void _insertOverlay(BuildContext context) {
return Overlay.of(context).insert(
OverlayEntry(builder: (context) {
final size = MediaQuery.of(context).size;
print(size.width);
return Positioned(
width: 56,
height: 56,
top: size.height - 72,
left: size.width - 72,
child: Material(
color: Colors.transparent,
child: GestureDetector(
onTap: () => print('ON TAP OVERLAY!'),
child: Container(
decoration: BoxDecoration(shape: BoxShape.circle, color: Colors.redAccent),
),
),
),
);
}),
);
}
}
class Page1 extends StatelessWidget {
final GlobalKey<NavigatorState> navigatorKey;
Page1(this.navigatorKey);
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.green[200],
appBar: AppBar(title: Text('Page1')),
body: Container(
alignment: Alignment.center,
child: RaisedButton(
child: Text('go to Page2'),
onPressed: () => navigatorKey.currentState.pushNamed('/page2'),
),
),
);
}
}
class Page2 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.yellow[200],
appBar: AppBar(title: Text('back to Page1')),
body: Container(
alignment: Alignment.center,
child: Text('Page 2'),
),
);
}
}
Screenshot (Null safe):
Full code:
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
Offset _offset = Offset.zero;
#override
Widget build(BuildContext context) {
return MaterialApp(
home: LoginPage(),
builder: (context, child) {
return Stack(
children: [
child!,
Positioned(
left: _offset.dx,
top: _offset.dy,
child: GestureDetector(
onPanUpdate: (d) => setState(() => _offset += Offset(d.delta.dx, d.delta.dy)),
child: FloatingActionButton(
onPressed: () {},
backgroundColor: Colors.black,
child: Icon(Icons.add),
),
),
),
],
);
},
);
}
}
LoginPage:
class LoginPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('LoginPage')),
body: Center(
child: ElevatedButton(
onPressed: () => Navigator.push(context, MaterialPageRoute(builder: (_) => HomePage())),
child: Text('Page2'),
),
),
);
}
}
HomePage:
class HomePage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('HomePage')),
body: FlutterLogo(size: 300),
);
}
}
After reading the comments, find github-repo-link
created an overlay that will sit on top of everything
that can be called from anywhere.
just 4 easy steps to follow
flutterflutter-layout
STEP-1: in main.dart:
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Stack( <-- using stack
children: [
MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
),
OverlayView(),<-- my overlay widget
],
),
);
}
}
STEP-2: OverLayView.dart
class OverlayView extends StatelessWidget {
const OverlayView({
Key key,
}) : super(key: key);
#override
Widget build(BuildContext context) {
return ValueListenableBuilder<bool>( <--- IMP , using ValueListenableBuilder for showing/removing overlay
valueListenable: Loader.appLoader.loaderShowingNotifier,
builder: (context, value, child) {
if (value) {
return yourOverLayWidget(); <-- your awesome overlay
} else {
return Container();
}
},
);
}
STEP-3: loder_controller.dart (to show/hide)
class Loader {
static final Loader appLoader = Loader(); <-- singleton
ValueNotifier<bool> loaderShowingNotifier = ValueNotifier(false);
ValueNotifier<String> loaderTextNotifier = ValueNotifier('error message');
void showLoader() { <-- using to show from anywhere
loaderShowingNotifier.value = true;
}
void hideLoader() { <-- using to hide from anywhere
loaderShowingNotifier.value = false;
}
void setText({String errorMessage}) { <-- using to change error message from anywhere
loaderTextNotifier.value = errorMessage;
}
void setImage() { <-- DIY
// same as that of setText //
}
}
FINAL STEP-4: show/hide loder
I'm showing it, on boilerplate code of increment method to show the loader
void _incrementCounter() async {
Loader.appLoader.showLoader(); <-- show loder
Loader.appLoader.setText(errorMessage: 'this is custom error message');<-- set custom message
await Future.delayed(Duration(seconds: 5)); <-- im hiding it after 5 sec
Loader.appLoader.hideLoader(); <-- do whatever you want
}
As a supplement to other answers: If you want to show some overlays, the flutter_portal may indeed be a better choice that is simpler to use.
Basically, it looks like:
PortalTarget(
// Declarative
portalFollower: MyAwesomeOverlayWidget(),
// Align anywhere you like. Now `portalFollower` floats at right of `child`
anchor: const Aligned(follower: Alignment.topLeft, target: Alignment.topRight),
child: MyChildWidget(),
)
Notice that it is declarative (not imperative as opposed to Overlay). Moreover, you get the bonus that the alignment is very easy, and the context is intuitive.
Disclaimer: I am the current owner of this library.
Have you tried to add a Navigator as a child/descendant of your Scaffold? As far as I remember, the default navigator is in the MaterialApp, which is above everything. When you add your own Navigator, your routing will happen under the Scaffold rather than above it in the tree.
I am trying to rebuild iOS app in Flutter, but facing a problem with navigation.
Here what I am trying to do:
List of Added Exchange Pairs with Add button (A screen)
Add button opens Picker with Exchanges (B screen) with transition from bottom to top.
By tapping on exchange it pushes new Picker with Pairs (C
screen) with transition from right to left.
when user taps on pair it closes all pickers at once and deliver result of picking to A screen.
I have tried double pop and popUntil but result always same, I see 2 back transitions (left to right and top to bottom) at same time.
How it looks in iOS native app:
How it looks in Flutter app:
Solved with nested Navigator
Wrapped Screen B with Navigator and used this navigator to push screen C, on screen C used root navigator to pop. Result is below:
Here the example of how I solved it:
import 'package:flutter/material.dart';
void main() {
MaterialPageRoute.debugEnableFadingRoutes = true;
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String _result = "--";
void _openSubscreen() {
Navigator.of(context).push<String>(
new MaterialPageRoute(
settings: RouteSettings(name: '/subscreen'),
builder: (context) => SubScreen(),
),
).then((result) => setState((){
_result = result;
}));
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Text(
'Result from navigator:',
),
new Text(
_result,
textAlign: TextAlign.center,
style: Theme.of(context).textTheme.headline,
),
SizedBox(height: 32.0,),
OutlineButton(
onPressed: _openSubscreen,
child: Text('Start flow'),
),
],
),
),
);
}
}
class SubScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: new Navigator(
onGenerateRoute: (routeSettings) {
final path = routeSettings.name;
if (path == '/') {
return new MaterialPageRoute(
settings: routeSettings.copyWith(isInitialRoute: true),
builder: (_) => SubScreenPage1(),
);
} else if (path == '/nexpage') {
return new MaterialPageRoute(
settings: routeSettings,
builder: (_) => SubScreenPage2(),
);
}
},
),
);
}
}
class SubScreenPage1 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Center(
child: OutlineButton(
child: Text('Next sub page!'),
onPressed: () {
Navigator.of(context).pushNamed('/nexpage');
},
),
);
}
}
class SubScreenPage2 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Center(
child: OutlineButton(
child: Text('Deliver result!'),
onPressed: () {
final date = DateTime.now().toString();
Navigator
.of(context, rootNavigator: true)
.pop('Delivered at $date');
},
),
);
}
}
When you build your MaterialApp by setting home: and routes: you can achieve "pop to root" without hardcoding what route to pop until by;
Navigator.popUntil(
context,
ModalRoute.withName(Navigator.defaultRouteName),
);
Because Navigator.defaultRouteName will be set to whatever you set home: to.
Going a bit off-topic but, this is especially nice if you have "variable" home screen, as in using a FutureBuilder to decide what will be the home screen. For example, if you are showing a splash screen until you are loading the initial state from disk.
home: isUserLoggedIn
? HomePage()
: FutureBuilder(
future: () async {
print('Initializing');
print('Waiting For NoReason');
await Future.delayed(const Duration(seconds: 1));
print('Initialization Complete');
}(),
builder: (_, snap) {
if (snap.connectionState == ConnectionState.waiting) {
return SplashPage();
} else {
return LogInPage();
}
},
),
I'm trying to start a new screen within an onTap but I get the following error:
Navigator operation requested with a context that does not include a
Navigator.
The code I am using to navigate is:
onTap: () { Navigator.of(context).pushNamed('/settings'); },
I have set up a route in my app as follows:
routes: <String, WidgetBuilder>{
'/settings': (BuildContext context) => new SettingsPage(),
},
I've tried to copy the code using the stocks sample application. I've looked at the Navigator and Route documentation and can't figure out how the context can be made to include a Navigator. The context being used in the onTap is referenced from the parameter passed into the build method:
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
SettingsPage is a class as follows:
class SettingsPage extends Navigator {
Widget buildAppBar(BuildContext context) {
return new AppBar(
title: const Text('Settings')
);
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: buildAppBar(context),
);
}
}
TLDR: Wrap the widget which needs to access to Navigator into a Builder or extract that sub-tree into a class. And use the new BuildContext to access Navigator.
This error is unrelated to the destination. It happens because you used a context that doesn't contain a Navigator instance as parent.
How do I create a Navigator instance then ?
This is usually done by inserting in your widget tree a MaterialApp or WidgetsApp. Although you can do it manually by using Navigator directly but less recommended. Then, all children of such widget can access NavigatorState using Navigator.of(context).
Wait, I already have a MaterialApp/WidgetsApp !
That's most likely the case. But this error can still happens when you use a context that is a parent of MaterialApp/WidgetsApp.
This happens because when you do Navigator.of(context), it will start from the widget associated to the context used. And then go upward in the widget tree until it either find a Navigator or there's no more widget.
In the first case, everything is fine. In the second, it throws a
Navigator operation requested with a context that does not include a Navigator.
So, how do I fix it ?
First, let's reproduce this error :
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Center(
child: RaisedButton(
child: Text("Foo"),
onPressed: () => Navigator.pushNamed(context, "/"),
),
),
);
}
}
This example creates a button that attempts to go to '/' on click but will instead throw an exception.
Notice here that in the
onPressed: () => Navigator.pushNamed(context, "/"),
we used context passed by to build of MyApp.
The problem is, MyApp is actually a parent of MaterialApp. As it's the widget who instantiate MaterialApp! Therefore MyApp's BuildContext doesn't have a MaterialApp as parent!
To solve this problem, we need to use a different context.
In this situation, the easiest solution is to introduce a new widget as child of MaterialApp. And then use that widget's context to do the Navigator call.
There are a few ways to achieve this. You can extract home into a custom class :
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHome()
);
}
}
class MyHome extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: RaisedButton(
child: Text("Foo"),
onPressed: () => Navigator.pushNamed(context, "/"),
),
);
}
}
Or you can use Builder :
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Builder(
builder: (context) => Center(
child: RaisedButton(
child: Text("Foo"),
onPressed: () => Navigator.pushNamed(context, "/"),
),
),
),
);
}
}
Hy guys, i have the same problem. This is occur for me. The solution what i found is very simple. Only what i did is in a simple code:
void main() {
runApp(MaterialApp(
home: YOURAPP() ,
),
);
}
I hope was useful.
Make sure your current parent widget not with same level with MaterialApp
Wrong Way
class HomeScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text('Title'),
),
body: Center(
child: Padding(
padding: EdgeInsets.symmetric(vertical: 8.0, horizontal: 16.0),
child: RaisedButton(
onPressed: () {
//wrong way: use context in same level tree with MaterialApp
Navigator.push(context,
MaterialPageRoute(builder: (context) => ScanScreen()));
},
child: const Text('SCAN')),
)),
),
);
}
}
Right way
void main() => runApp(MaterialApp(
title: "App",
home: HomeScreen(),
));
class HomeScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text('Title'),
),
body: Center(
child: Padding(
padding: EdgeInsets.symmetric(vertical: 8.0, horizontal: 16.0),
child: RaisedButton(
onPressed: () {
//right way: use context in below level tree with MaterialApp
Navigator.push(context,
MaterialPageRoute(builder: (context) => ScanScreen()));
},
child: const Text('SCAN')),
)),
);
}
}
Just like with a Scaffold you can use a GlobalKey. It doesn't need context.
final _navKey = GlobalKey<NavigatorState>();
void _navigateToLogin() {
_navKey.currentState.popUntil((r) => r.isFirst);
_navKey.currentState.pushReplacementNamed(LoginRoute.name);
}
#override
Widget build(BuildContext context) {
return MaterialApp(
navigatorKey: _navKey,
...
);
}
I set up this simple example for routing in a flutter app:
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
home: new MyHomePage(),
routes: <String, WidgetBuilder>{
'/settings': (BuildContext context) => new SettingsPage(),
},
);
}
}
class MyHomePage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('TestProject'),
),
body: new Center(
child: new FlatButton(
child: const Text('Go to Settings'),
onPressed: () => Navigator.of(context).pushNamed('/settings')
)
)
);
}
}
class SettingsPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('SettingsPage'),
),
body: new Center(
child: new Text('Settings')
)
);
}
}
Note, that the SettingsPage extends StatelessWidget and not Navigator. I'm not able to reproduce your error.
Does this example help you in building your app? Let me know if I can help you with anything else.
You should rewrite your code in main.dart
FROM:
void main() => runApp(MyApp());
TO
void main() {
runApp(MaterialApp(
title: 'Your title',
home: MyApp(),));}
The point is to have the home property to be your first page
this worked for me, I hope it will help someone in the future
A complete and tested solution:
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:my-app/view/main-view.dart';
class SplashView extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: Builder(
builder: (context) => new _SplashContent(),
),
routes: <String, WidgetBuilder>{
'/main': (BuildContext context) => new MainView()}
);
}
}
class _SplashContent extends StatefulWidget{
#override
_SplashContentState createState() => new _SplashContentState();
}
class _SplashContentState extends State<_SplashContent>
with SingleTickerProviderStateMixin {
var _iconAnimationController;
var _iconAnimation;
startTimeout() async {
var duration = const Duration(seconds: 3);
return new Timer(duration, handleTimeout);
}
void handleTimeout() {
Navigator.pushReplacementNamed(context, "/main");
}
#override
void initState() {
super.initState();
_iconAnimationController = new AnimationController(
vsync: this, duration: new Duration(milliseconds: 2000));
_iconAnimation = new CurvedAnimation(
parent: _iconAnimationController, curve: Curves.easeIn);
_iconAnimation.addListener(() => this.setState(() {}));
_iconAnimationController.forward();
startTimeout();
}
#override
Widget build(BuildContext context) {
return new Center(
child: new Image(
image: new AssetImage("images/logo.png"),
width: _iconAnimation.value * 100,
height: _iconAnimation.value * 100,
)
);
}
}
As per this comment If your navigator is inside Material context navigator push will give this error. if you create a new widget and assign it to the material app home navigator will work.
This won't work
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
appBar: new AppBar(
title: new Text("Title"),
),
body: new Center(child: new Text("Click Me")),
floatingActionButton: new FloatingActionButton(
child: new Icon(Icons.add),
backgroundColor: Colors.orange,
onPressed: () {
print("Clicked");
Navigator.push(
context,
new MaterialPageRoute(builder: (context) => new AddTaskScreen()),
);
},
),
),
);
}
}
This will work
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new HomeScreen());
}
}
class HomeScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text("Title"),
),
body: new Center(child: new Text("Click Me")),
floatingActionButton: new FloatingActionButton(
child: new Icon(Icons.add),
backgroundColor: Colors.orange,
onPressed: () {
print("Clicked");
Navigator.push(
context,
new MaterialPageRoute(builder: (context) => new AddTaskScreen()),
);
},
),
);
}
}
I was facing the same problem and solved by removing home from MaterialApp and use initialRoute instead.
return MaterialApp(
debugShowCheckedModeBanner: false,
initialRoute: '/',
routes: {
'/': (context) => MyApp(),
'/settings': (context) => SettingsPage(),
},
);
And
onTap: () => {
Navigator.pushNamed(context, "/settings")
},
It is Simple
instead using this normal code
`runApp(BasicBankingSystem());`
wrap it with MaterialApp
runApp(MaterialApp(home: BasicBankingSystem()));
It happens because the context on the widget that tries to navigate is still using the material widget.
The short answer for the solution is to :
extract your widget
that has navigation to new class so it has a different context when calling the navigation
When your screen is not navigated from other screen,you don't initially have access to the navigator,Because it is not instantiated yet.So in that case wrap your widget with builder and extract context from there.This worked for me.
builder: (context) => Center(
child: RaisedButton(
child: Text("Foo"),
onPressed: () => Navigator.pushNamed(context, "/"),
),
You ca use this plugin
https://pub.dev/packages/get/versions/2.0.2
in The MaterialApp assign property navigatorKey: Get.key,
MaterialApp(
navigatorKey: Get.key,
initialRoute: "/",
);
you can access Get.toNamed("Your route name");
Change your main function example:
void main() {
runApp(
MaterialApp(
title: 'Your title',
home: MyApp(),
)
);
}
use this
void main() {
runApp(MaterialApp(debugShowCheckedModeBanner: false, home: MyApp()),);
}
instead of this
void main() {runApp(MyApp());}
Wrap with materialapp
reproduce code
import 'dart:convert';
import 'package:flutter/material.dart';
void main() {
// reproduce code
runApp(MyApp());
// working switch //
// runApp(
//
// MaterialApp(debugShowCheckedModeBanner: false, home: MyApp()),);
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
body:
Column(mainAxisAlignment: MainAxisAlignment.center, children: [
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Container(
height: 100,
width: 100,
child: ElevatedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => IntroPage(Isscar4: true)),
);
},
child: RichText(
text: TextSpan(
text: 'CAR',
style: TextStyle(
letterSpacing: 3,
color: Colors.white,
fontWeight: FontWeight.w400),
children: [
TextSpan(
text: '4',
style: TextStyle(
fontSize: 25,
color: Colors.red,
fontWeight: FontWeight.bold))
],
)),
),
),
],
),
SizedBox(
height: 10,
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Container(
height: 100,
width: 100,
child: ElevatedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => IntroPage(Isscar4: false)),
);
},
child: RichText(
text: TextSpan(
text: 'BIKE',
style: TextStyle(
letterSpacing: 3,
color: Colors.white,
fontWeight: FontWeight.w400),
children: [
TextSpan(
text: '2',
style: TextStyle(
fontSize: 25,
color: Colors.red,
fontWeight: FontWeight.bold))
],
)),
),
),
],
)
])));
}
MaterialApp Swithwidget(istrue) {
return MaterialApp(
home: Scaffold(
body: IntroPage(
Isscar4: istrue,
),
),
);
}
}
class Hi extends StatelessWidget {
const Hi({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Container(
child: Text("df"),
);
}
}
class IntroPage extends StatelessWidget {
final Isscar4;
IntroPage({
Key? key,
required this.Isscar4,
}) : super(key: key);
List<Widget> listPagesViewModel = [];
List<IntroModel> models = [];
#override
Widget build(BuildContext context) {
List<dynamic> intro = fetchIntroApi(Isscar4);
intro.forEach((element) {
var element2 = element as Map<String, dynamic>;
var cd = IntroModel.fromJson(element2);
models.add(cd);
});
models.forEach((element) {
listPagesViewModel.add(Text(""));
});
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
body: Container(),
));
}
List fetchIntroApi(bool bool) {
var four = bool;
if (four) {
var data =
'[ {"name_Title": "title name1","description": "description1"}, {"name_Title": "title name2","description": "description2"}, {"name_Title": "title name3","description": "description3"}, {"name_Title": "title name4","description": "description4"} ]';
return json.decode(data);
} else {
var data =
'[ {"name_Title": "title name","description": "description1"}, {"name_Title": "title name2","description": "description2"}, {"name_Title": "title name3","description": "description3"} ]';
return json.decode(data);
}
}
}
class IntroModel {
String? nameTitle;
String? description;
IntroModel({this.nameTitle, this.description});
IntroModel.fromJson(Map<String, dynamic> json) {
nameTitle = json['name_Title'];
description = json['description'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['name_Title'] = this.nameTitle;
data['description'] = this.description;
return data;
}
}
class Splash extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Splash Screen',
theme: ThemeData(
primarySwatch: Colors.green,
),
home: MyState(),
debugShowCheckedModeBanner: false,
);
}
void main() {
runApp(Splash());
}
class MyState extends StatefulWidget{
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyState> {
#override
void initState() {
super.initState();
Timer(Duration(seconds: 3),
()=>Navigator.pushReplacement(context,
MaterialPageRoute(builder:
(context) =>
Login()
)
)
);
}
#override
Widget build(BuildContext context) {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center ,
children: [
Container(
child:
Image.asset("assets/images/herosplash.png"),
),
],
),
);
}
}
Builder(
builder: (context) {
return TextButton(
child: const Text('Bearbeiten'),
onPressed:(){
Navigator.push(
context,
MaterialPageRoute(builder: (context) => const gotothesiteyouwant()),
);
});
}
),
Here, all you need is to make MaterialApp the parent of your Build. This is because the context that you've used to navigate to a different screen is finding a MaterialApp or a WidgetApp as a parent of the build.
And Since in your case, the situation is the opposite, therefore you need to modify it by either calling a new Stateless widget the parent of is the MaterialApp or by simply using a Builder as home: Builder in MaterialApp.
Hope this would help!