Most voted "flutter" questions
Flutter is a mobile application development SDK created by Google.
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answers1502
viewsHow to get the value of the variable outside the Future method in Flutter?
I am developing in a book app and am stuck on the screen where will open the file . pdf. I need to get the path of the mobile directory using path_provider to send to pdfviewer but I can’t get the…
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answers408
viewsHow to use distinct to bring a single result of each Dart/Flutter item
Hello, I am trying to bring a single result of each consuming title from an API. As this picture shows I’m having repeated titles What way could I make it right, it follows code as far as I’ve tried…
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answers689
viewsHow do I select this in the Firebase Cloud Firestore database?
how do I do this kind of select in the Firebase Cloud Firestore database ? _results = (await connection.query('select id from produtos where numero_serie = $_numeroSerie')) I need to get the product…
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answer1836
viewsHow to change the color of an Icon through Boolean Return in Flutter?
I have a method that queries books that are favorite in the Firestore database, the book page has a star icon in black color, use isFavorite method to query whether the open book is preferred by the…
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answer309
viewsUse more than one Firebase database in an app created in Flutter
Good evening Guys, I’m designing an app and I’m thinking about using flutter and Firebase. My project consists of a customer register where each company can have its customer portfolio online. Is…
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answer42
viewsParameters Firebase bank
The flutter has to communicate with firebase the file google-services.json, would have some way to send parameters with the key of another firebase database and projectid?
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answers4738
viewsFlutter, how to compile the project to run native on android
I’m starting in Flutter, I would like to know how to compile my project to be a native application, such as for Android. How can I do this from the command line? I found Andoid studio very…
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answer68
viewsWhat could be the mistake?
FAILURE: Build failed with an exception. * What went wrong: Could not determine the dependencies of task ':app:compileDebugJavaWithJavac'. > Could not create service of type…
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answers71
viewsHow to dynamically leave . package configuration in flutter
How to leave dynamic the configuration of . package in flutter, by default of my machine (Windows) is like this: async:file://C:/flutter_windows_v1.5.4-Hotfix.2-stable/flutter/.…
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answer1014
viewsFormat Duration - Timer
I am trying to format in Dart/Flutter the timer a certain time elapsed, whose code: Duration _tempo = new Duration(); Text('Tempo: ${_tempo.inHours}:${_tempo.inMinutes}:${_tempo.inSeconds}'), The…
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answer173
viewsTextfield flutter using Cupertino theme
I need to do a search bar next to this field "Contacts": child: CustomScrollView( //semanticChildCount: totalRows, slivers: <Widget>[ CupertinoSliverNavigationBar( largeTitle:…
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answer949
viewsHow do I get every Gridview Card in flutter to open a specific link?
Do I need to know how to differentiate one card from another in Gridview from the flutter? Because I need to open, as soon as clicked, a specific link for each card. I have a code that opens a…
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answer166
viewsconcatenate a link in a Map
I receive data from an API of The Movie DB, of which I must take an image link,the movie poster. The problem is that the data of this image only generates me half the link. Code: class…
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answer1814
viewsKeep login active on flutter
I want when the user logs in, even if the application is still logged in. I am using an own api made in Nodejs. Through my researches I saw that you can do this using the plugin Sharedpreferences.…
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answer430
viewsDeserialize JSON - Dart/Flutter
I have a JSON and want to play it in an array. final String jsonSample='[{"id":1},{"id":2}]'; var json = jsonDecode(jsonSample); print (json); //resultado é: [{id: 1}, {id: 2}] So far so good, but…
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answer222
viewsHeader in an http.send request
I have a request by stream which is as follows:. Future<Stream<Chamado>> getChamado() async{ final String url = 'www.api' final client = new http.Client(); final streamRest = await…
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answer737
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answers488
viewsVoidcallback x Function what’s the difference?
In the documentation it states that part of dart.ui; /// Signature of callbacks that have no arguments and return no data. typedef VoidCallback = void Function(); From what I understand VoidCallback…
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answer76
viewsFlutter Data Passage
I have a button that makes a request get on a server. Data passing is correct however at the time I try to recover in the build class of error. class Layout_ResultadoExames extends StatefulWidget{…
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answer182
viewsHow do I disable the stagehand template when creating a web flutter project?
I’ve tried to disable using the command pub global deactivate stagehand , however I cannot create any project if this template is not enabled. Vscode asks if you want to activate it using the…
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answer278
viewsPrintar or draw widget with flutter
I have the following dialog and would like to generate a "voucher" so that the person could share it, as if it were proof of payments that the bank applications generate. I managed to take a "print"…
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answers1129
viewsError while trying to install the application in flutter on physical mobile
I’m having trouble installing my application on my physical phone(Redmi 6 note PRO), I’ve done some tests and the problem is in the plugin authentication with facebook, flutter_facebook_login, if I…
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answers1988
viewsScrollview with a Fixed Container in the Footer - Flutter
I would like a Scrollview with a fixed container in the footer because in it I will position a banner of admob but I cannot fix this container I want it to be independent of the scrollview and…
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answer2121
viewsSimple GET request to a Rest API in flutter
I’m trying to get a json by making a request to an API, but it’s making a mistake when making the request. Follows the code: Future<Map> timeStamp() async { const request =…
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answer38
viewsHow to apply Sliverappbar class code to Flutter
I found in Flutter’s documentation the Sliverappbar. However, as I am starting with Flutter, I have doubts about how and where to insert the code within my project in Flutter. Should I create a…
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answer38
viewscall a file by Listtile
I have an apparently simple doubt (difficult for me as a beginner), but I created a navigation Drawer, and in this Drawer has the Listtile, I need to know how to call a file by this list. ListTile(…
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answers417
viewsDoubts onPressed integration with Google Maps Flutter
I set up a canvas and I’m having a hard time doing something On the buttons I wanted to put to work onPressed linked to the google maps API. Like, when I click on one of the buttons, it will tell me…
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answer290
viewsWidget Slider and flutter_staggered_grid_view Slider
How to individualize the actions of these Widget Slides? The problem is that when I slip one, the other also reacts as if it were a clone. I’m using the "flutter_staggered_grid_view Slider 3.0…
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answer52
viewsDartime Format (month name with minuscule letter)
I am formatting the following date "2020-03-25" and I want it to come out "March 25" but with my formatting it is coming out "March 25" the name of the month is coming out with minuscule letter, it…
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answer169
viewsThe Schedule function of the local flutter notification does not work, does anyone know what it might be?
import 'package:flutter/cupertino.dart'; import 'package:flutter/material.dart'; import 'package:flutter_local_notifications/flutter_local_notifications.dart'; import…
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answer83
viewsFlow of change notification
I have already understood how the process of changing the state of a widget where it is 'updated' to show its new value. However, the documentation speaks of the flow, that is, the path that is…
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answers860
viewsDeserializar json vector in Dart/Flutter
I’m trying to deserialize this json vector [{"i":737,"n":1}] but I’m not getting the variables "i" and "n". Class to deserialize class PortasAbertas { int i; int n; PortasAbertas({this.i, this.n});…
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answers2045
viewsFlutter - How do I change the color of the Expanded only clicked. Thank you?
Row( children: lists .map((element) => Expanded( child: new GestureDetector( onTap: () { print("Container clicked"); setState(() { _doop = element; …
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answer548
viewsDart/Flutter verification/validation in the Firebase Firestore database
I’m trying to do a Dart/Flutter check/validation in the Firebase Firestore database to not save the same serial number string twice in the database, but I’m doing something wrong because it keeps…
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answer241
viewsHow to make only the user who saved the String can see Flutter/Firebase?
This is a code that saves a String qr code that does not repeat in the database, but this way everyone can access this data. I already got the user ID but I still can’t filter to just see the list.…
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answers331
viewsIterate in Map<List, String>
How to iterate on a Mapof the kind Map<List, String>? List all values, pay key value: [1, 'A']. void main() { print(_mapList.map); //?? // _mapList.map((i, s) =>{ // }); } Map<List,…
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answer204
viewsHow to define Dart parameter
class Checkbox extends StatelessWidget { final String title = 'Checkbox'; // final String value ='CheckboxValue'; @override Widget build(BuildContext context)…
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answer409
viewsError when converting json with object lists to a Dart object
Good morning to you all! I am getting the following error while trying to convert a json to Dart. [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: type '_Internallinkedhashmap' is…
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answers70
viewsDo codes in the console debug have any meaning?
I would like to know if there is any documentation that explains in more detail what that means I/flutter,etc, and the code in parentheses. Sometimes it goes unnoticed in debug exception and on the…
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answers4378
viewsPositioning in flutter columns
I have the following code on the flutter: import 'package:flutter/material.dart'; class LoginPage extends StatefulWidget { @override _LoginPageState createState() => _LoginPageState(); } class…
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answer186
viewsInsert Image after Gridview
I’m developing an APP on flutter using a Staggeredgridview at the beginning of the build, but I’m not able to insert an image before this grid. import 'package:flutter/material.dart'; import…
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answer445
viewsListview.Uilder does not update when removing an item from the list, but when adding yes
I have a Future Builder that takes a list, and then returns a column with a Listview.Builder() and a button below, when using the button to add an element the list updates successfully, now when…
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answer246
viewsHow do I know if my development environment is compatible with Androidx?
My project was created long ago and I don’t know if it is compatible with Androidx how could I identify it? And how to upgrade to make it compatible with Androidx? (I am using vscode)
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answers161
viewsFlutter Hot Reload no activating - Waiting for Observatory port to be available
When running any application in flutter (on terminal, android studio or visual code) on my Android device LG K11 Android Nougat, the flutter process does not pass this line: Waiting for observatory…
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answer182
viewsIn a Flutter application on Android Studio an error message is displayed when modifying something in the build.Radle
FAILURE: Build failed with an Exception. This error occurs when I modify something in the build.Radle of the "app" folder of some Flutter application in Android Studio. So, just clicking on the…
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answer57
viewsError in android genymotion emulator (linux): Httpexception: Connection closed before full header was Received, Uri = http://127.0.0.1
I have the following error while running an android flutter project, I noticed that if I leave my code without letters in the text class, the code will run. An example: import…
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answer463
viewsRedirect via button to website - Flutter
You can redirect the user after clicking a button to a website, directly opening the browser or even a webview. From onPressed. Container( alignment: Alignment.center, child: FlatButton( onPressed:…
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answer241
viewsAndroid Studio 4.0 incomparable Flutter Plugin
Android Studio has reached version 4.0, however before updating warns that the flutter and Dart plugin are incompatible with the new version of Android Studio. Has anyone tried any solution, or just…
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answers24
viewsHow to discover possible Exceptions?
Example, in http requests we can have SocketException, TimeoutException,etc. In I/O operations we also have other possible Exceptions. Not to have to treat in a generic way, ex: catch (e), how to…
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answers159
viewsText widget displays only 1 character
I’m starting flutter now, and in my first App (which should display random phrases as you press a button) it’s giving a problem, rather than displaying sentences, it displays only a single…