Most voted "flutter" questions
Flutter is a mobile application development SDK created by Google.
Learn more…510 questions
Sort by count of
-
-1
votes1
answer39
viewsWB How to make use of Android Studio Profile?
When we are working on Android development with Java or Kotlin usually it is using a feature similar to Listview, but on Android devices if the list is too large the application starts to load too…
-
-1
votes2
answers928
viewsFLUTTER ERROR - The method '[]' was called on null
I’m starting with Flutter, and I stumbled upon the mistake The method '[]' was called on null. I am testing an api to return the data, but I always get this error. The strange thing is that if I…
-
-1
votes1
answer316
viewsmissingpluginexception(no implementation found for method distanceBetween on Channel flutter/baseflow.com/geolocator.methods
When trying to calculate a freight using the distance from the registered ZIP code to the user, I come across this error: missingpluginexception(no implementation found for method distanceBetween on…
-
-1
votes1
answer574
viewsCarousel Flutter
Hello! I developed a Carousel in flutter. I would like to know two things - even because I have tried and failed. First, if it is possible to place on the image that is displayed in the Carousel a…
-
-1
votes1
answer228
viewsMemory management/cloud image storage by Flutter
I recently started developing an App on Flutter and am trying to understand how it uses device memory/storage in relation to cloud-hosted images. To better contextualize is a Market App, the…
-
-1
votes1
answer351
viewsTake the return value of a Datepicker on a texFormField with flutter
Good afternoon! I’m starting my studies in Flutter and I created a simple form, where when clicking on a date field, it displays the datepicker, but when selecting the date the field is not filled.…
-
-1
votes2
answers516
viewsbuild_runner does not execute the flutter pub run build_runner build --delete-Conflicting-outputs --verbose command
Hello, I created a project with the flutter create command. as I will use modular to activated the slidy in the project with the slidy start command so far so good, but when I try to run the command…
-
-1
votes1
answer365
viewsHow to put background images in the same listtitle in this Flutter image
return Card( margin: EdgeInsets.all(5.0), elevation: 2, child: Container( child: ListTile( leading: task.situacao == true ? Icon( Icons.thumb_up, color: Colors.green, size: 30, ) : Icon(…
-
-1
votes2
answers670
viewsFlutter Dart -> Capturing data from a class that receives json
Good guys? I’m a beginner in flutter, and I’m working on a ready-made template. In this template I have the class Category.Dart that receives the json values of service.Dart and so far everything is…
-
-1
votes1
answer98
viewsHow to send notification to all Onesignal users with Flutter
Hello! I’m learning notifications with flutter and oneSignal. I figured out how to send notifications to specific users, but I don’t know how to send them to multiple users. My code so far is this:…
-
-1
votes1
answer39
viewsVariable is not being decremented as the line excluded through Dismissible
I have a ListView.builder returning a ListTile, adding the time at title and value "10" in trailing every time the "ADD +10" button is triggered. I used the widget Dismissible to delete items, but I…
-
-1
votes1
answer40
viewsHow can I use Gesture with Gridview?
I need help when the user clicks on the image, open the corresponding page. import 'package:flutter/material.dart'; import 'package:health/page-health/doador.dart'; import…
-
-1
votes1
answer73
viewsAndroid Studio stopped working after installing Flutter and this error infirmmation
Good morning! I had Android Studio installed on my machine and after installing Flutter it stopped working. I uninstalled Flutter and even then Android Studio does not work and only presents this…
-
-1
votes1
answer262
viewsCan anyone solve this error by building a flutter project?
I built my flutter project and came across this mistake someone can help me? C: src flutter bin flutter.bat --no-color build apk Running "flutter pub get" in auto_home... 1,6s You are building a fat…
-
-1
votes1
answer28
viewsReturn repeated in action on the flutter login screen
bool _login; Future<bool> login(String email, String senha) async { var response = await http.get("http://192.168.0.116:5001/usuarios/login/$email/$senha"); if(response.statusCode == 200) {…
-
-1
votes1
answer15
viewsHow to center both?
I am learning flutter now, and I am making this app very simple and I would like to know how I can centralize these 2 widgets in the center and regardless of the size of the number always stay…
flutterasked 3 years, 9 months ago Barney Dulirou 9 -
-1
votes1
answer17
viewsTake the size of the firestore array to use in Listview.Builder itemcount
return Scaffold( body: StreamBuilder( stream: stream, builder: (context, snapshot) { if (snapshot.hasData) { return ListView.builder( itemCount: snapshot.data.docs.length, itemBuilder: (context,…
-
-1
votes1
answer106
viewsFlutter [ Datatable ]
I am new to Flutter programming. I have assembled a page that when calling via menu I would like to present the data in a Datatable. I even managed to do this, but only presents the data when I…
-
-1
votes1
answer81
viewsAccess data in Firebase with Flutter
I am trying to access the data according to the image. I need to bring the information that is inside the document. I’m trying to use the following code: final QuerySnapshot result1 = await…
-
-1
votes1
answer48
viewsProblem for alignment
I have a problem, I can’t put the Radiolisttile next to an image, when I try to put it looks like this: You can take a look at my code and see what’s wrong: Scaffold( body: Container( padding:…
-
-1
votes1
answer63
viewsFlutter Dart: return value for a class
When calling the method callReadTotal(), the global variable tot receives the value and it prints without problems its result within it. However, in the class ThemesList called it, the variable…
-
-1
votes1
answer27
viewsWhite space between gridview.Builder items
My gridView.Builder has a blank space between the inexplicable lines, I’ve reviewed all the code and there is no widget with this margin or padding. Is Gridview coming with auto space? If so, how do…
-
-1
votes1
answer138
viewsFirebase does not sort list by date correctly
I am filtering some documents by date/time to retrieve the latest items first. However, when adding a new item to the list it is added correctly, but when restarting the app the list is redone and…
-
-1
votes1
answer45
viewsTrigger a tab function from another widget
Communication between screens is essential in an application. In this case I am trying to conduct a search from a Searchdelegate But when I return from the Searchdelegate I cannot communicate with…
-
-1
votes1
answer82
views -
-1
votes2
answers1817
viewsError: The argument type 'String? ' can’t be Assigned to the Parameter type 'String' because 'String? ' is nullable and 'String' isn’t
In the code I’m doing, is being mounted an if to know if a certain age is greater or smaller and show the messages, so far so good. The point is, when I use the integer value, I can work normally,…
-
-1
votes0
answers28
viewsVERBOSE-2:ui_dart_state. cc(199) Unhandled Exception: type 'Future<Map<String? , Dynamic>? >'
[VERBOSE-2:ui_dart_state.cc(199)] Unhandled Exception: type 'Future<Map<String?, dynamic>?>' is not a subtype of type 'FutureOr<Map<String?, dynamic>>' in type cast #0…
flutterasked 3 years, 3 months ago Diego Daniel 11 -
-1
votes0
answers22
viewsHow to enter Realtime Database data into my Flutter app
I’m a beginner in Flutter and I’m wondering how to work with the Realtime Database in a project I’m part of, I wanted to know how to take this data from the image of the database and put in the…
-
-2
votes1
answer227
viewsHow to convert a string with special characters into utf8?
I’m not getting to decode the characters that appear in this string with Dart. import 'dart:convert'; void main(){ var myString="Data de coleta superior &agrave; 15 dias n&atilde;o…
-
-2
votes1
answer161
viewsHow to create an "Asset" Vscode directory in a Flutter project
I’m starting to learn Flutter and, I need to create an "Assets" directory at the root of the flutter project in Vscode, but I can’t, just give me the option to create new Files and new folders. if…
flutterasked 4 years, 1 month ago Marcio Guilherme 1 -
-2
votes2
answers3211
viewsConversion of values into flutter
I need to take a figure that comes from a field like text. However, this field only receives numbers. Text field: Container( child: CupertinoTextField( textCapitalization: TextCapitalization.none,…
-
-2
votes1
answer102
viewsMobx does not generate Dart file.
Hello, recently my project from scratch simply started not generating the file .g.Dart when I import some class in the model, even the classes that were already imported if I leave it error and does…
-
-2
votes1
answer23
viewsProblem with android studio using flutter
I can’t run my project in android studio emulator…
-
-2
votes1
answer60
viewsFirebase cloud firestore random query with specific user ID (Flutter)
I’m trying to randomly pull my data from the firestore cloud but I’m not getting it, does anyone know how to do it using ID? getQustoes(String simuladoId) async{ return await…
-
-2
votes1
answer317
viewsProblem to recover UID from firebase Authentication?
I am trying to create a collection in Firebase and for the document of this collection I would like to take the authentication UID of the user registration, the registration of the authentication is…
-
-2
votes1
answer75
viewsBurst of memory - Flutter
While trying to unzip a 500MB zip file using the package Archive, I’m having memory problems (Out of memory). Follow the code for evaluation and suggestion of some alternative. unarchiveAndSave(var…
-
-2
votes3
answers1630
viewsUpdate data on Setstate() Flutter page, enter Loop
I’m having trouble updating the status I’m taking a list and showing her If I put Setstate in _getProdPro loops, if I don’t put, the data is not updated on the screen, someone knows how I can call…
-
-2
votes1
answer83
viewsDropdownbutton does not work when searching for the Db async Future using the Widget: Future Builder Flutter
Exception that appears: Exception Caught by widgets library The following was thrown building Futurebuilder(Dirty, state: _Futurebuilderstate#74679): type '(City) => Dropdownmenuitem' is not a…
-
-2
votes1
answer1701
viewsFlutter: Row Alignment
Good afternoon, everyone! I’m starting now to learn to mess with flutter, and I’m having doubts about the alignment of the words underneath the Suspected and Investigated cards. I would like to…
-
-2
votes1
answer645
views<<Flutter>> Doubt on return of Map - //Map <String, Dynamic>// - this returning: null
I will leave the code block --(Recovers api from https://viacep.com.br/, data listed on Cod, end of studies and training) import 'package:flutter/material.dart'; import 'package:http/http.dart' as…
-
-2
votes1
answer93
viewsError converting firebase to json with flutter Dart
Good afternoon, you guys, This firebase screen was working perfectly, but as I created an API and am migrating to json, I am not being able to convert this screen and I would like your help! The…
-
-2
votes2
answers235
viewsDoubt Flutter: Listview
Good morning! Could someone assist me in a doubt? What am I doing: I did a search for the user to search for an Infringement or Attachments etc in the app, and soon after the action on the keyboard…
-
-2
votes1
answer270
viewsWait for an asynchronous function to finish to continue
I can expect an asynchronous terminal function to continue the code? I have an asynchronous function with a Try/catch and want to catch the bug to treat. Login(BuildContext context) async { try {…
-
-2
votes1
answer226
viewsProvider Flutter: Exception Caught by widgets library
All right ? I’m having an error after adding an initState with Provider I no longer know what to do, I did everything and did not solve my problem, really I’m lost! After I added this snippet in my…
-
-2
votes1
answer1467
viewsFlutter: Container with two Expanded and a background image
UPDATED WITH THE ENTIRE SCREEN CODE I wonder if anyone can help me with this? I have a Listview, and in the construction of your itemBuilder, I intend to have a Container divided by two Expanded.…
-
-2
votes1
answer42
viewsMethod cartReference Returning Null (in my firebase has the Subcollection 'Cart', within the 'Users' Collection)
I’m days away with this problem, I’m making a delivery app, time to add the product to the cart, it tells me it’s returning Null the method cartReference, but when I click again on the button " add…
-
-2
votes2
answers116
viewsRecover value if null in Flutter Sharedpreferences
I’m learning to flutter these days. I’m studying Shared Preferences: When I save to Shared Preferences and retrieve the information, it works, but when I remove and try to retrieve the information,…
-
-2
votes1
answer55
viewsBottomnavigatorbar is not accepting pages. How to fix?
I’m trying to make an app that uses Bottomnavigatorbar as a tool to navigate between screens, but by placing a page to be executed after clicking on one of the menu icons, it’s returning a string…
-
-2
votes1
answer81
views6 positional argument(s) expected, but 1 found. Try Adding the Missing FLUTTER
I’m developing a screen that sends information to a Rest C api# However from the following error 6 positional argument(s) expected, but 1 found. Try Adding the Missing Follows code: import…
-
-2
votes1
answer118
viewsListview is not displayed below a 'Container'
I’m new to the flutter and I’m having a hard time showing a Listview below a Container. In the codex lattice below is displayed only mine Container, and the Listview just doesn’t show up. Obs: no…