In later versions, you can use kDebugMode: if (kDebugMode) doSomething(); While asserts can technically be used to manually create an “is debug mode” variable, you should avoid that. Instead, use the constant kReleaseMode from package:flutter/foundation.dart The difference is all about tree shaking. Tree shaking (aka the compiler removing unused code) depends on variables being constants. … Read more
You can do with little Trick: Suppose you have requirement of : ( Width,Height ) Wrap_content ,Wrap_content : //use this as child Wrap( children: <Widget>[*your_child*]) Match_parent,Match_parent: //use this as child Container( height: double.infinity, width: double.infinity,child:*your_child*) Match_parent,Wrap_content : //use this as child Row( mainAxisSize: MainAxisSize.max, children: <Widget>[*your_child*], ); Wrap_content ,Match_parent: //use this as child Column( mainAxisSize: … Read more
Import package:flutter/services.dart, then Put the SystemChrome.setPreferredOrientations inside the Widget build() method. Example: class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { SystemChrome.setPreferredOrientations([ DeviceOrientation.portraitUp, DeviceOrientation.portraitDown, ]); return new MaterialApp(…); } } Update This solution mightn’t work for some IOS devices as mentioned in the updated flutter documentation on Oct 2019. They Advise to fixed the … Read more
This is a supplemental answer showing the implementation of a couple of the solutions mentioned. FractionallySizedBox If you have a single widget you can use a FractionallySizedBox widget to specify a percentage of the available space to fill. Here the green Container is set to fill 70% of the available width and 30% of the … Read more
According to the official documentation: @Deprecated(“Use a list literal, [], or the List.filled constructor instead”) NOTICE: This constructor cannot be used in null-safe code. Use List.filled to create a non-empty list. This requires a fill value to initialize the list elements with. To create an empty list, use [] for a growable list or List.empty … Read more
Question 1: You first need to store the images picked by using ImagePicker (or MultiImagePicker plugin) in a collection. Here’s an example on how to do that: List<File> images = List<File>(); images.add(await ImagePicker.pickImage(source: ImageSource.gallery, imageQuality: 20);); When you want to show those images on the screen, you can use several different widgets, like ListView, GridView, … Read more
Try below answer hope its help to you. you can refer my answer here and here also for data comes from API and display it into dropdown. Declare variables: String? sid; List data = []; var urls = “https://parallelum.com.br/fipe/api/v1/carros/marcas”; Your API call function: Future fetchData() async { var result = await http.get(Uri.parse(urls), headers: { ‘Content-Type’: … Read more
Create a StatelessWidget say MyArc which accepts a diameter. import ‘dart:math’ as math; class MyArc extends StatelessWidget { final double diameter; const MyArc({Key key, this.diameter = 200}) : super(key: key); @override Widget build(BuildContext context) { return CustomPaint( painter: MyPainter(), size: Size(diameter, diameter), ); } } // This is the Painter class class MyPainter extends CustomPainter … Read more
Don’t stock context directly into custom classes, and don’t use context after async if you’re not sure your widget is mounted. Do something like this: class MyCustomClass { const MyCustomClass(); Future<void> myAsyncMethod(BuildContext context, VoidCallback onSuccess) async { await Future.delayed(const Duration(seconds: 2)); onSuccess.call(); } } class MyWidget extends StatefulWidget { @override _MyWidgetState createState() => _MyWidgetState(); } … Read more
Right now this issue is opened on github https://github.com/flutter/flutter/issues/32587 Temporarily you can solve this issue by switching to physical device instead of emulator How to test android apps in a real device with Android Studio? Decision found on github (link upward) I’ve got a temporary work around, which I can use for now. The exception … Read more