dart

Dart timeout on await Future

由 自闭症网瘾萝莉.ら 提交于 2020-12-29 13:18:02
问题 How to make a await future not last more than 5 seconds ? I need it because in some networking operation, the connection is sometimes producing silent error. Hence my client just wait for hours with no response. Instead, I want it trigger an error when the clients waits for more than 5 seconds My code can trigger the error but it is still waiting Future shouldnotlastmorethan5sec() async { Future foo = Future.delayed(const Duration(seconds: 10));; foo.timeout(Duration(seconds: 5), onTimeout: (

Dart timeout on await Future

由 旧城冷巷雨未停 提交于 2020-12-29 13:17:34
问题 How to make a await future not last more than 5 seconds ? I need it because in some networking operation, the connection is sometimes producing silent error. Hence my client just wait for hours with no response. Instead, I want it trigger an error when the clients waits for more than 5 seconds My code can trigger the error but it is still waiting Future shouldnotlastmorethan5sec() async { Future foo = Future.delayed(const Duration(seconds: 10));; foo.timeout(Duration(seconds: 5), onTimeout: (

Dart timeout on await Future

由 ぃ、小莉子 提交于 2020-12-29 13:17:14
问题 How to make a await future not last more than 5 seconds ? I need it because in some networking operation, the connection is sometimes producing silent error. Hence my client just wait for hours with no response. Instead, I want it trigger an error when the clients waits for more than 5 seconds My code can trigger the error but it is still waiting Future shouldnotlastmorethan5sec() async { Future foo = Future.delayed(const Duration(seconds: 10));; foo.timeout(Duration(seconds: 5), onTimeout: (

Triggering initial event in BLoC

由 帅比萌擦擦* 提交于 2020-12-29 13:12:38
问题 example_states: abstract class ExampleState extends Equatable { const ExampleState(); } class LoadingState extends ExampleState { // } class LoadedState extends ExampleState { // } class FailedState extends ExampleState { // } example_events: abstract class ExampleEvent extends Equatable { // } class SubscribeEvent extends ExampleEvent { // } class UnsubscribeEvent extends ExampleEvent { // } class FetchEvent extends ExampleEvent { // } example_bloc: class ExampleBloc extends Bloc

手把手教你玩转Flutter之Flutter环境搭建

由 不想你离开。 提交于 2020-12-29 11:37:25
手把手教你玩转Flutter之Flutter环境搭建 文章目录 目录 前言 一、配置国内镜像 二、下载Flutter SDK 1.官网下载 2.配置环境变量 3.验证Flutter是否安装成功 三、安装配置Android Studio 1.安装Android Studio 2.安装Flutter和Dart插件 3.检查Flutter环境 四、第一个Flutter应用 1.搭建Flutter应用 2.运行Flutter应用 3.常见问题记录 参考资料： 前言 Flutter 是 Google 开源的 UI 工具包，帮助开发者通过一套代码库高效构建多平台精美应用，支持移动、Web、桌面和嵌入式平台。 同时，通过Flutter框架开发的移动端应用，可以在Anroid和IOS中完美使用，不需要再单独开发Android或IOS版本，目前Flutter已经成为移动端开发热门的工具。 提示：本文是以Windows为例，记录了在Windows操作系统中构建Flutter开发环境的步骤。 一、配置国内镜像 Flutter官方为国内开发者设立了镜像，在开始配置Flutter环境时，首先要进行配置。需要我们在环境变量中加入如下两个环境变量： export PUB_HOSTED_URL=https://pub.flutter-io.cn export FLUTTER_STORAGE_BASE_URL

How to get ByteData from a File

由 流过昼夜 提交于 2020-12-29 09:53:18
问题 I want to convert a File to a ByteData object in flutter. Something like this: import 'dart:io'; File file = getSomeCorrectFile(); //This file is correct ByteData bytes = ByteData(file.readAsBytesSync()); //Doesnt compile return bytes; I understood that ByteData constructor receives the length of the amount of bytes and initialize them with 0, so I could do something like ByteData(file.readAsBytesStync().length); but then how do I fill them? What am I missing? 回答1: In Dart 2.5.0 or later, I

Flutter - Is it possible to extract data from a Future without using a FutureBuilder?

由 ↘锁芯ラ 提交于 2020-12-29 09:02:53
问题 I'm reading in user-provided input (in this case a zip code) from a TextField that I need to check against a database for validity. However, I need to make an asynchronous database query inside of the submit button's (a RaisedButton in this case) onPressed: () {} lambda function. In most programming languages, this is a fairly straightforward and simple task. The problem I'm running into in Flutter, however, is the fact that Future objects returned from asynchronous database queries can only

How to run a code-generator on the top of another code-generator?

由 ℡╲_俬逩灬. 提交于 2020-12-29 05:28:47
问题 Using the source_gen stack to make a code generator, how can I make a generator that generates code that would be the input of another generator (more specifically json_serializable )? For example, consider: class Example extends Generator { @override String generate(LibraryReader library, BuildStep buildStep) { return ''' @JsonSerializable(nullable: false) class Person { final String firstName; final String lastName; final DateTime dateOfBirth; Person({this.firstName, this.lastName, this

Flutter: ListView not scrollable, not bouncing

由 ⅰ亾dé卋堺 提交于 2020-12-29 05:16:22
问题 I have the following example (tested on an iPhone X, iOS 11): import 'package:flutter/material.dart'; void main() => runApp(new MyApp()); class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return new MaterialApp( title: 'Flutter Demo', theme: new ThemeData( primarySwatch: Colors.blue, ), home: new MyHomePage(title: 'Flutter Demo Home Page'), ); } } class MyHomePage extends StatefulWidget { MyHomePage({Key key, this.title}) : super(key: key); final String

Flutter: ListView not scrollable, not bouncing

由 荒凉一梦 提交于 2020-12-29 05:13:01
问题 I have the following example (tested on an iPhone X, iOS 11): import 'package:flutter/material.dart'; void main() => runApp(new MyApp()); class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return new MaterialApp( title: 'Flutter Demo', theme: new ThemeData( primarySwatch: Colors.blue, ), home: new MyHomePage(title: 'Flutter Demo Home Page'), ); } } class MyHomePage extends StatefulWidget { MyHomePage({Key key, this.title}) : super(key: key); final String
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