Most voted "flutter" questions
Flutter is a mobile application development SDK created by Google.
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answers13
viewsHow to use Dart.Dio to make a get request by passing parameters on the body?
Problem happens with flutter, using the Dio 4.0.0 package I am using it as follows, however it presents error 414 (Dioerrortype.Response). Ps.: Using Postman with same address and parameter values…
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answers22
viewsProblem "Instance Member can’t be accessed using Static access." in a simple registration system
I’m trying to create a registration system and for some reason I can’t access the "put" (add) method, located in the "users.Dart", on the screen where the entries are shown, the "cadastros.Dart".…
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answers11
viewsdisplay data stored on sqfliter in flutter
Personal I am trying to display data that I take from sqlfliter and display in a listview but always gives error: [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: type 'int' is not…
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answer353
viewsConvert Brazilian to American date to parse for a Date object
I’m making an application that reads an html page and gets some information, among them a date. This date is in Portuguese, in the following format: "23 March 2019". I wonder if you have any way to…
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answer121
viewsError to return Dart/flutter value
Good evening, you guys. I am trying to learn how to use Bloc with rxdart. I am having difficulty recovering the value of the API When debugging does not know if an Exception appears it follows…
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answer601
viewsFlutter: Error when adding more than 3 items to a Listview
Hello, all the Listview of my application in Flutter if add more than 3 items occurs to Exception below: I/flutter (13259): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY…
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answer733
viewsError to recover a Future List<Class> Dart
People are having trouble recovering data from a future function when arriving in snapshot... presents this error: AsyncSnapshot<List<Episodio>>(ConnectionState.done, null, Exception:…
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answer272
viewsEfficiency of Firebase
Guys, I have a question, and I’m not finding anything on the internet, I’m making an application for a client and I’m using firebase, for being a google server I believe it will withstand the high…
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answer518
viewsDay Scrolling for Month Scrolling
Good night! I have this example of day scrolling that makes the user scroll through the dates of the month with each click both forward and backward. However, I would like that, instead of every…
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answers524
viewsWhy this mistake in decorating my container on the flutter?
Cannot provide Both a color and a Decoration The color argument is just a shorthand for "Decoration: new Boxdecoration(color: color)". 'package:flutter/src/widgets/container.Dart': Failed assertion:…
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answer982
viewsNosuchmethoderror: The Setter 'gasoline=' was called on null
Good morning, I have an error that I cannot solve in my application, I need to make a calculation with the values received in certain attributes, but the attribute does not receive the values, I get…
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answers371
viewsPlacing Dynamic Width in a Container
Hello! I’m wanting to use this control to replace the Dropdown, but I realized that its width command 'does not work', maybe by the context external to it, I didn’t get it right. Because I want to…
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answer308
viewsFlutter cannot find pubspec.yaml when running run run
I did the installation of Dart + flutter for the first time today, I did the Getting Start oriented configuration of the official website itself, but when giving RUN in the project, this error…
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answer1687
viewsBottom Overflowed
import 'package:flutter/material.dart'; //import 'package:font_awesome_flutter/font_awesome_flutter.dart'; //import 'package:flutter/widgets.dart'; //import…
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answer54
viewsAs I inform a condition for when the screen is changed the timer.Eriodic cancel
Today I use so with the code below, but it doesn’t work very well, because when changing screen the query continues to be executed in background. Future _refresh() async { if (_statusLote !=…
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answers352
viewsWhat mistake is this and what can I do to fix it?
Error: ADB exited with Exit code 1 Performing Streamed Install adb: failed to install C: pedidos build app outputs apk app.apk: Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package with.ample…
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answer1039
viewsasync x await x Future
What are Keywords for async and await in Flutter? Some doubts I have are: 1 - They belong to Flutter or Dart? 2 - Why put the async at the end of the following method? void _method(TodoItem item)…
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answer479
viewsHow to limit a composite query in Firebase/flutter
I made a simple query this way and works correctly, it saves only once in the database, not repeating the same value. final QuerySnapshot result = await Future.value(Firestore.instance…
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answer47
viewsWhat is the difference between the versions shown Flutter doctor and Vscode?
The flutter doctor command shows: [ ] Flutter (Channel stable, v1.17.0, on Microsoft Windows Already in vscode it shows: Flutter: 1.12.13+Hotfix.9 What is the difference between these versions?…
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answer189
viewsHow do I use the value of a variable in other places?
I’m getting a value from a variable that is passed through a route, but I want to take that value and put it into another code block. File 1 final String nomeCategoria; File 2…
flutterasked 4 years, 6 months ago William Gravina 15 -
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answer1221
viewsError with Map<String, Dynamic> - Cannot recognize String as Dynamic
I have the following Flutter error: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'String' This error is occurring when I have run the code seginte: List…
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answer132
viewsDatetime.Parse returning wrong time
Hi, I’m doing this: DateTime horaInicio = DateTime.parse(parsedJson['comeco']); Value of parsedJson: As you can see in parsedJson it’s 7:38:33 and this is the time I wanted, but I have as an answer:…
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answer599
viewsFlutter calling a dialog inside an onTap()
I’m having a problem in a APP development on flutter, I’m trying to call a method inside an onTap(); however this presenting the following error: "The Return type 'void' isn’t a 'Widget', as defined…
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answer345
viewsUpdate to Flutter/Dart database
I need to change only the comment field of a contact. But when I try to change this field accuses this error type 'int' is not a subtype of type 'Client'. I wonder why, since the update function…
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answer384
viewsHow to access the changed value of a variable of another class?
I have two classes, my app’s home screen class (Homescreen) and my button class (Button). I have this function in my button class: bool variável = false; void alterarValor() { setState((){ variável…
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answer29
viewsI am creating a flutter registration app and is giving this error what should I do? can anyone please help me?
A non-null string must be provided to a text widget. 'package: flutter / src / widgets / text.Dart': Failed assertion: line 360 pos 10: 'data! = Null'
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answer198
viewsError trying to change the configured Locale using a Dart library
I’m trying to set up a new one locale on another screen of the application, but it says that the object I try to access is null, but I did exactly as the example, I’m not finding the error.…
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answer381
viewsPass Values through Stream / Bloc
I have a login_bloc.Dart file and within it I have the following situation. final usuario = BehaviorSubject<String>(); usuario.sink.add(user.email); and in the file home_screen.Dart, I have…
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answer95
viewsError in calculation - Flutter
I am cracking my head in a problem that is giving in my debug in an application of mine which is as follows: "The method '>' was called on null. Receiver: null Tried Calling: >(0)" Follow the…
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answers15
viewsFlutter FIRESTORE INTERNAL ASSERTION FAILED: threads > 1
I’m having a problem with my flutter app on iOS. When I Try to make a call to get data from a Collection, the application ends with the error: FIRESTORE INTERNAL ASSERTION FAILED: threads > 1…
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answer73
viewsZeroing a slider’s default margin on flutter
How do I reset the margins of a slider in the flutter Slider( value: valueHolder.toDouble(), min: 0, max: 100, divisions: 100, activeColor: Colors.green, inactiveColor: Colors.grey, label:…
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answer3464
views(Solved) ERROR: Flutter Unhandled Exception: type 'Future<Dynamic>' is not a subtype of type 'List<Oficioenviado>
I’m trying to make an Infinit scroll, I have a consumption of an api where I take the data and convert with my model to json, I want to insert this data in variable, where when arriving at the end…
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answer197
viewsHow to save value correctly in Sharedpreferences? - Flutter
Hello, everybody! Where am I going wrong? I have login with google to pick up the token and send to graphgl. This token is saved - at least that’s what it should be - in sharedpreferences, but it’s…
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answer906
viewsUpdate a Listview in a Statefulwidget Son Flutter
my main layout features an aapBar, body and bottomNavigationBar through the bottomNavigationBar I update the body with other screens, which show a listview, in the appBar from the main screen I have…
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answer73
viewsUsing value returned in function to create a listview flutter
I have a function that accesses the Firestore and returns a list, when I click on a button this function is called and should create a lisrviwerbuilder(). But I don’t know why he doesn’t create.…
flutterasked 4 years, 8 months ago Fernando Foster 121 -
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answer139
viewsProblem compiling apk on flutter - R8: Program type already present
I’m trying to compile apk to flutter, but am getting error in R8, I already have other applications in flutter never had problem to compile, making the tests realize that the problem is being the…
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answer1565
viewsFlutter - A Renderflex overflowed by 572 pixels on the bottom
Hello, I have had some mistakes with Flutter when it comes to the issue of OVERFLOW of the edges. I made a Listview.Uilder and it has been overflowing vertically. What I tried and didn’t work: Wrap…
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answers225
viewsDifficulty writing in cloud firestore
I managed to configure my android project to firebase, but when I test the firestore cloud nothing happens. I’m trying to write a text in the database,. main: import 'package:flutter/material.dart';…
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answer854
viewsNavigation between flutter screens
I have the following code, which is called in main.Dart to display, and I would like to navigate to another screen(class), but when I use routes, when I call the element navigator, he of the error…
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answer430
viewsHow to show a push notification on the iOS lock screen using flutter and FCM
I followed several tutorials and am unable to show on the lock screen on iphone the notification using flutter and FCM. I followed the steps: I enabled my app on my apple account for notifications I…
ios flutter xcode firebase-cloud-messagingasked 4 years, 7 months ago Roberto Luiz Teixeira Rocha 71 -
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answer151
viewsHow do I display a notification badge when I receive a notification?
Hello, in my application I have a list that shows the users who sent messages. I want to place a notification badge when the user receives a notification. Any idea how I can get such a function?…
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answer567
viewsOld projects with error after Flutter update
A Flutter update was made using the command: git clone -b stable https://github.com/flutter/flutter.git After this update, some old projects have several bugs (here are some of them): List _toDoList…
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answer282
viewspushNavigator - Dart/Flutter
Hello, I’m learning how to develop Dart/Flutter apps. What happens is that I pressed a Navigator.push, where it loads the previous route, in case I want to return, however, in my appbar instead of…
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answer88
viewsFilter and do not pick up repeated firestore data on flutter
I have in the Firestore the following given. user1 = {'horário':'manhã'} user2 = {'horário':'manhã'} user3 = {'horário':'tarde'} user4 = {'horário':'manhã'} user5 = {'horário':'tarde'} I create…
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answer118
viewsDoubt Flutter: Listview duplicate data
Good morning! Could someone assist me in a doubt? What am I doing: I made a search for the user to search for an Infraction in the app, and right after the action on the keyboard I redirect it to…
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answer385
viewsPassage of parameter through the modular
I am not knowing how to pass the file parameter home_page to the archive produtos_module when the user clicks. home_page.Dart file Observer( builder: (_) { List<CategoriaModel> categoria =…
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answer33
viewsLogo does not appear on the flutter inside the Gradient container
I’m trying to put my logo on the login page of my app, but I’m not getting it. Obs.: I am beginner in language and I’m adapting to widgets. return Scaffold( body: Center( child: Container(…
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answer345
viewsHow to create a Listview.Separated correctly
The problem is below the two images, and the whole code is at the end. Hello, I’m trying to create a list of widgets horizontally, as shown in the following image I get a little big, sorry, but…
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answer37
viewsPicking up new information from a website and adding a new line with this information every time it is updated
hello guys I’m trying to get data from a site api(own server) and so show the new data in the application as soon as the site makes an update with new information, thus adding a new line and keeping…
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answer576
viewsHow to put text under Boxdecoration Flutter
Hello! I’d like to do the following : A list that shows people online, with their name down. Only I managed to do the following: I would like to put a name underneath the image of the person. I…