Sort a list of objects in Flutter (Dart) by property value
You can pass a comparison function to List.sort. someObjects.sort((a, b) => a.someProperty.compareTo(b.someProperty));
flutter
How do I bold (or format) a piece of text within a paragraph?
You should use the RichText widget. A RichText widget will take in a TextSpan widget that can also have a list of children TextSpans. Each TextSpan widget can have a different TextStyle. Here is the example code to render: Hello World var text = RichText( text: TextSpan( // Note: Styles for TextSpans must be explicitly … Read more
How to set Custom height for Widget in GridView in Flutter?
The key is the childAspectRatio. This value is use to determine the layout in GridView. In order to get the desired aspect you have to set it to the (itemWidth / itemHeight). The solution would be this: class MyHomePage extends StatefulWidget { MyHomePage({Key key, this.title}) : super(key: key); final String title; @override _MyHomePageState createState() => … Read more
How to center the title of an appbar
Centering the title is the default on iOS. On Android, the AppBar‘s title defaults to left-aligned, but you can override it by passing centerTitle: true as an argument to the AppBar constructor. Example: AppBar( centerTitle: true, // this is all you need … )
Flutter: Setting the height of the AppBar
You can use PreferredSize: class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( title: ‘Example’, home: Scaffold( appBar: PreferredSize( preferredSize: Size.fromHeight(50.0), // here the desired height child: AppBar( // … ) ), body: // … ) ); } }
Enumerate or map through a list with index and value in Dart
There is a asMap method which converts the list to a map where the keys are the index and values are the element at index. Please take a look at the docs here. Example: List _sample = [‘a’,’b’,’c’]; _sample.asMap().forEach((index, value) => f); Hope this helps!
How to get height of a Widget?
To get the size/position of a widget on screen, you can use GlobalKey to get its BuildContext to then find the RenderBox of that specific widget, which will contain its global position and rendered size. Just one thing to be careful of: That context may not exist if the widget is not rendered. Which can … Read more
Flutter how to programmatically exit the app
Below worked perfectly with me in both Android and iOS, I used exit(0) from dart:io import ‘dart:io’; @override Widget build(BuildContext context) { return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new … (…), floatingActionButton: new FloatingActionButton( onPressed: ()=> exit(0), tooltip: ‘Close app’, child: new Icon(Icons.close), ), ); } UPDATE Jan 2019 Preferable … Read more
Cannot run with sound null safety because dependencies don’t support null safety
First, you should read through the guide to understand unsound null safety. If you are sure that you want to run your application with unsound null safety, you can use the following command: flutter run –no-sound-null-safety The –no-sound-null-safety option is not documented in the article, however, I have not experienced any problems with it for … Read more
How to downgrade Flutter SDK (Dart 1.x)
Flutter is versioned using git. Changing the Flutter version is as simple as changing git branch. There are 2 different ways: flutter channel <branch> (example: flutter channel stable) This command is used to change between branches – usually stable/dev/beta/master. We can also put a specific commit id from git. flutter downgrade <version> (example: flutter downgrade … Read more