Most voted "dart" questions
Dart is a web-based language developed by Google. The goal of the Dart language is to replace Javascript as the main language of browsers. Programs in this language can be either run on a virtual machine or compiled for Javascript.
Learn more…410 questions
Sort by count of
-
-1
votes1
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…
-
-1
votes1
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…
-
-1
votes1
answer41
viewsSubtraction result with double many decimal places appear
I’m starting at Dart and went to perform a simple subtraction operation with double but the result is very strange. For example in a subtraction of a salary of 3000 minus the ceiling of inss of…
-
-1
votes1
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…
-
-1
votes1
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 =…
-
-1
votes1
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…
-
-1
votes1
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…
-
-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
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
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
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
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
answer131
viewsError: Try correcting the name to one that is defined, or Defining the name
I am doing a small project using Dart, only that there is an error in my file ImprimirResultado.dart. Error Undefined name 'Imcformated'. Try correcting the name to one that is defined, or Defining…
-
-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
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
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
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
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
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
answers19
viewsHow to do a Listview filter search in Flutter?
How can I make a filter for searching this code? import 'package:flutter/material.dart'; import 'package:intl/date_symbol_data_local.dart'; import 'package:intl/intl.dart'; import…
-
-1
votes0
answers24
viewsConvert Python time to Dart
I’m making an application for study I took the data from this api https://www.mercadobitcoin.com.br/trade-api/#get_order and I’m converting to Dart. I have the error of {"status_code": 203,…
-
-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
answer94
viewsDifficulty writing a REGEX to validate URL
I’m having trouble creating a regular expression that validates the following URL: https://firebasestorage.googleapis.com/v0/b/nome-app/* *would be anything! Someone could give me a related surpote?…
-
-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
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
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
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
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
answer272
viewsHow to mount an XML string with SOAP?
I don’t know how to ride STRING of XML correct way to send the parameters with xml. According to the documentation the method is called coletar() but I am not able to pass these parameters…
-
-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
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
answer32
viewsMultiline string problem for twitter API in Dart
I’m creating a bot that tweets on Dart. I’m having problems because I want to post with line break but I can’t, the following error appears when I try to convert a string into json through the…