I am creating an app using Flutter.
On iOS however (you can also test it on Android), dark theme is not applied.
Using Android widgets, it is working fine tho.
How can I make the Cupertino widgets using the dark theme? Especially for the popups.
I am using Flutter 1.9.1+hotfix6
E.g. the Cupertino "ActionSheet":
import 'package:flutter/material.dart';
import 'home.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData.dark(),
darkTheme: ThemeData.dark(),
home: Home(),
);
}
}
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
class Home extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: RaisedButton(
child: Text('test'),
onPressed: () {
Widget secondaryButton, confirmButton, popup;
secondaryButton = CupertinoActionSheetAction(
child: Text('secundary'),
onPressed: () {},
);
confirmButton = CupertinoActionSheetAction(
child: Text('test'),
onPressed: () {},
);
popup = CupertinoActionSheet(
title: Text('Title'),
message: Text('Content'),
cancelButton: secondaryButton,
actions: [confirmButton],
);
showCupertinoModalPopup(
context: context, builder: (context) => popup);
},
),
);
}
}
Screenshot:
Check this repo, you can create platform specific layouts only using a single widget that does all the platform specific boilerplate for you.
Also have support for dark mode, at least in iOS.
I am trying out flutter, here I am having a simple card view, where there is an add AddButton , when the button is pressed new card is being added.
Now, i wanted to have it scrollable so added ListView and an expanded Widget in the Column. Here is the code...
import 'package:flutter/material.dart';
import './products.dart';
import './product_control.dart';
class ProductManger extends StatefulWidget {
final String startingProduct;
ProductManger({this.startingProduct = "Sweet Tester"});
#override
State<StatefulWidget> createState() {
return _ProductManagerState();
}
}
class _ProductManagerState extends State<ProductManger> {
List<String> _products = ['Food Tester'];
#override
void initState() {
_products.add(widget.startingProduct);
super.initState();
}
void _addProducts(String product) {
setState(() {
_products.add(product);
});
}
#override
Widget build(BuildContext context) {
return Column(children: [
Container(margin: EdgeInsets.all(10.0), child: ProductControl(_addProducts)),
Expanded(child: Products(_products))
]);
}
}
If I change that Expanded to Container with height, it works as expected, but now, nothing is being displayed except a button.
I am currently following a tutorial, exact same code is written, however, version of flutter is 0.3.2 and i am using 1.5
Or there could be some issue with the emulator?
Hope this helps.
Here is the listView code
import 'package:flutter/material.dart';
class Products extends StatelessWidget {
final List<String> products;
Products([this.products = const []]);
#override
Widget build(BuildContext context) {
return ListView(
children: products
.map((element) => Card(
child: Column(
children: <Widget>[
Image.asset('assets/food.jpg'),
Text(element)
],
),
))
.toList());
}
}
This is what is visible when i use Container with height 300.0 insted to expand
And when i use expand, this is what being shown
Please try to change
#override
Widget build(BuildContext context) {
return Column(children: [
Container(margin: EdgeInsets.all(10.0), child: ProductControl(_addProducts)),
Expanded(child: Products(_products))
]);
}
To
#override
Widget build(BuildContext context) {
return SingleChildScrollView(
child: Column: children: [
Container(
margin: EdgeInsets.all(10.0),
child: ProductControl(_addProducts)),
Expanded(child: Products(_products))
]);
}
If it does not work , Please give a look to SingleChildeScrollView
Ok, so after hours of time I found out finally, the error was in my main.dart file.
Initially, the code was
import 'package:flutter/material.dart';
import './product_manager.dart';
import 'package:flutter/rendering.dart';
void main(){
debugPaintSizeEnabled=true;
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(
primarySwatch: Colors.deepOrange,
accentColor: Colors.deepPurple
),
home: Scaffold(
appBar: AppBar(
title: Text("Alpit anand"),
),
body: Column(
children: [ProductManger()],
)),
);
}
}
But when i changed to
import 'package:flutter/material.dart';
import './product_manager.dart';
import 'package:flutter/rendering.dart';
void main(){
debugPaintSizeEnabled=true;
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(
primarySwatch: Colors.deepOrange,
accentColor: Colors.deepPurple
),
home: Scaffold(
appBar: AppBar(
title: Text("Alpit anand"),
),
body:
ProductManger(),
),
);
}
}
Thanks to pskink, you really helped me out. Thanks for your time. Although I still have to find out, why it wasn't working that way.
I am new to flutter so here is my code where its printing one centre text but I need a button under the text.
import 'package:flutter/material.dart';
void main()
{
runApp(MaterialApp(
title: 'Hello Flutter',
home: HomeWidget(),
));
}
class HomeWidget extends StatelessWidget
{
#override
Widget build(BuildContext context)
{
return Material(
child: Container(child: Center(child: Text('Hello World Of Flutter Development'),),),
// Need Button Here beneath Text
);
} //Widget
} //End of Class
use - Column Widget.
Learn more about drawing Layouts:
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(
title: 'Hello Flutter',
home: HomeWidget(),
));
}
class HomeWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Column(mainAxisAlignment: MainAxisAlignment.center,children: <Widget>[
Center(
child: Text('Hello World Of Flutter Development'),
),
RaisedButton(onPressed: (){},child: Text('Button'),) // Button under Text
]),
);
} //Widget
}
Use Column Widget
Column(
children: [
Text('Hello World Of Flutter Development'),
FlatButton(onPressed:() {}, child:Text('name on button')),
],
)
I want to use a Row to display some Text then the LinearProgressIndicator in a row, using this code:
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget { #override Widget build(BuildContext context) {
return MaterialApp(
title: 'MaterialApp',
home: Scaffold(
body: SafeArea(child: Row(
children: <Widget>[
Text('Start row'),
LinearProgressIndicator(),
],
),)),
); } }
The problem is nothing is displayed when I wrap the Text and the LinearProgressIndicator in a Row.
I can only get the Row to display the Text when I delete LinearProgressIndicator. And I can only get the LinearProgressIndicator to display when the Row is not used like this:
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'MaterialApp',
home: Scaffold(
body: SafeArea(child: LinearProgressIndicator(),)),
);
}
}
This is what the app looks like without the Row.
You should set a width for LinearProgressIndicator widget when it's inside a row widget. the error in console explained it very clear:
BoxConstraints forces an infinite width.
These invalid constraints were provided to RenderCustomPaint's layout() function by the following
function, which probably computed the invalid constraints in question:
Every unbounded widget should be wrapped inside widgets like Expanded or Flexible:
In this case:
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'MaterialApp',
home: Scaffold(
body: SafeArea(
child: Row(
children: <Widget>[
Center( // this widget is not nessesary
child: Text('Some text'),
),
Expanded(child: LinearProgressIndicator()),
],
),
)),
);
}
}
There is also a discussion here related to this matter.
I'm learning Flutter, and I'm starting from the very basics. I'm not using MaterialApp. What's a good way to set the background color of the whole screen?
Here's what I have so far:
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new Center(child: new Text("Hello, World!"));
}
}
Some of my questions are:
What's a basic way to set the background color?
What exactly am I looking at, on the screen? Which code "is" the background? Is there a thing to set the background color on? If not, what's a simple and appropriate "simple background" (in order to paint a background color).
Thanks for the help!
The code above generates a black screen with white text:
You can set background color to All Scaffolds in application at once.
Just set scaffoldBackgroundColor: in ThemeData:
MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(scaffoldBackgroundColor: const Color(0xFFEFEFEF)),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
I think you can also use a scaffold to do the white background. Here's some piece of code that may help.
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Testing',
home: new Scaffold(
//Here you can set what ever background color you need.
backgroundColor: Colors.white,
),
);
}
}
Here's one way that I found to do it. I don't know if there are better ways, or what the trade-offs are.
Container "tries to be as big as possible", according to https://flutter.io/layout/. Also, Container can take a decoration, which can be a BoxDecoration, which can have a color (which, is the background color).
Here's a sample that does indeed fill the screen with red, and puts "Hello, World!" into the center:
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new Container(
decoration: new BoxDecoration(color: Colors.red),
child: new Center(
child: new Text("Hello, World!"),
),
);
}
}
Note, the Container is returned by the MyApp build(). The Container has a decoration and a child, which is the centered text.
See it in action here:
There are many ways of doing it, I am listing few here.
Using backgroundColor
Scaffold(
backgroundColor: Colors.black,
body: Center(...),
)
Using Container in SizedBox.expand
Scaffold(
body: SizedBox.expand(
child: Container(
color: Colors.black,
child: Center(...)
),
),
)
Using Theme
Theme(
data: Theme.of(context).copyWith(scaffoldBackgroundColor: Colors.black),
child: Scaffold(
body: Center(...),
),
)
You should return Scaffold widget and add your widget inside Scaffold
Such as this code:
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
body: Center(child: new Text("Hello, World!"));
);
}
}
Scaffold(
backgroundColor: Constants.defaulBackground,
body: new Container(
child: Center(yourtext)
)
)
It's another approach to change the color of background:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(home: Scaffold(backgroundColor: Colors.pink,),);
}
}
On the basic example of Flutter you can set with backgroundColor: Colors.X of Scaffold
#override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
backgroundColor: Colors.blue,
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add_circle),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
I think you need to use MaterialApp widget and use theme and set primarySwatch with color that you want. look like below code,
import 'package:flutter/material.dart';
void main() {
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'),
);
}
}
home: Scaffold(
backgroundColor: Color(
0xBF453F3F),
and done :)
You can just put the six digit hexa after (0xFF**......**):
return Scaffold(
backgroundColor: const Color(0xFFE9ECEF),
.....) } )
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Your App',
theme: ThemeData(
scaffoldBackgroundColor: Colors.black,
),
home HomeScreen(),
);
}
}
Sample code:
import 'package:flutter/material.dart';
void main() {
runApp(
MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('Sample App'),
backgroundColor: Colors.amber, // changing Appbar back color
),
backgroundColor: Colors.blue, // changing body back color
),
),
);
}
As sirelon suggested, add scaffold color in the theme like this,
theme: new ThemeData(scaffoldBackgroundColor: const Color(0xFFEFEFEF)),
or can give color to individual scaffold like this
Scaffold(
backgroundColor: Color(0xFFF1F1F1),
...
);
Try the following code:
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(
scaffoldBackgroundColor: Colors.white, // Change the background color of all Scaffold widgets of your app here
),
home: const Scaffold(
body: Center(child: Text("Hello, World!")),
backgroundColor: Colors.white, // Change the background color of this Scaffold widget here
),
);
}
}