flutter-provider

问题 Hello? I'm building an app using the flutter provider pattern. And I created a process to query the values ​​inside the object. I also have data in my model dart file. Check the code below. List<Device> _devices = [ Device(one: 'apple', two: 'iphone'), Device(one: 'samsung', two: 'galaxy') ]; String Query(String value) { return _media.where((medium) => medium.one == value) .map((medium) => (medium.two)).toString(); Query("apple") So, when I call that function, I expect iphone to be returned.

问题 Hello? I'm building an app using the flutter provider pattern. And I created a process to query the values ​​inside the object. I also have data in my model dart file. Check the code below. List<Device> _devices = [ Device(one: 'apple', two: 'iphone'), Device(one: 'samsung', two: 'galaxy') ]; String Query(String value) { return _media.where((medium) => medium.one == value) .map((medium) => (medium.two)).toString(); Query("apple") So, when I call that function, I expect iphone to be returned.

问题 I am currently having an issue while fetching a Provider' value in initstate`. I want to set a default value in dropdown in an Appbar and other parts in body. But I got an error saying dependOnInheritedElement() was called before initstate() in flutter . My full code is below main.dart import 'package:test_eoil/model/button_data.dart'; import 'package:test_eoil/model/output_data.dart'; import 'screen/screen.dart'; import 'package:flutter/material.dart'; import 'package:provider/provider.dart'

问题 I am currently having an issue while fetching a Provider' value in initstate`. I want to set a default value in dropdown in an Appbar and other parts in body. But I got an error saying dependOnInheritedElement() was called before initstate() in flutter . My full code is below main.dart import 'package:test_eoil/model/button_data.dart'; import 'package:test_eoil/model/output_data.dart'; import 'screen/screen.dart'; import 'package:flutter/material.dart'; import 'package:provider/provider.dart'

问题 I'm new to flutter and I'm trying to create an app with provider. I wrapped MaterialApp widget with the ChangeNotifierProvider and the app works and I can use the provider as it intended to do. I need to know is it okay to do so and will i face any problems? Widget build(BuildContext context) { return ChangeNotifierProvider<BaseModel>( builder: (context) => BaseModel(loading: false, title: "Title", isLoggedIn: false), child: MaterialApp( routes: <String, WidgetBuilder>{ "/home": (BuildContext

问题 I am deleting a engine model via: delete(int id) { engines.removeWhere((eng) => eng.id == id); notifyListeners(); } } The interesting part here is that the engine with the passed id gets removed indeed correctly while debugging. But visually seen the wrong eengine widget gets deleted and I have no idea why??? I put here all code which can be easily copy/paste into the famous main.dart file! I am new to flutter and even more to provider package. Maybe I have done something wrong there...

问题 @override Widget build(BuildContext context) { return WillPopScope( onWillPop: () async { return false; }, child: Stack( children: <Widget>[ DefaultTabController( length: 5, child: ChangeNotifierProvider( builder: (context) => MySchedule(), child: ( Scaffold( appBar: AppBar( actions: <Widget>[ Container( width: MediaQuery.of(context).size.width, child: Row( mainAxisAlignment: MainAxisAlignment.spaceBetween, children: <Widget>[ GestureDetector( onTap: () async{ await Navigator.of(context).push

问题 I am building my first big app in Flutter, and the first one where I need State Management, so I turned to Provider which is the recommended package to use for State Management. However I am having some issues where I declare my Providers in the main.dart file and down the tree I want to make changes and interact with one of the Providers but no matter what solution I try, I keep getting the same error: "Tried to listen to a value exposed with provider, from outside of the widget tree.". I

问题 I am building my first big app in Flutter, and the first one where I need State Management, so I turned to Provider which is the recommended package to use for State Management. However I am having some issues where I declare my Providers in the main.dart file and down the tree I want to make changes and interact with one of the Providers but no matter what solution I try, I keep getting the same error: "Tried to listen to a value exposed with provider, from outside of the widget tree.". I

问题 I am trying to implement custom logout solution for my application, where no matter where user currently is, once the Logout button is clicked, app will navigate back to Login page . My idea was, that instead of listening on every component for state changes, I would have one single listener on a master component -> MyApp . For the sake of simplicity, I have stripped down items to bare minimum. Here is how my Profile class could look like: class Profile with ChangeNotifier { bool