Flutter

flutter使用provider简单实现计数器

由 走远了吗. 提交于 2021-02-06 14:31:37
1，首先在pubspec.yaml里面安装 2，在同一个页面创建两个widget（或者将这两个widget单独创立dart文件） import 'package:flutter/material.dart'; import 'dart:async'; import 'package:provider/provider.dart'; import '../../provide/cunter.dart'; class StrictsSelection extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( body: Center( child: Column( children: [ Number(), MyButton() ], ), ), ); } } class Number extends StatelessWidget { @override Widget build(BuildContext context) { return Container( margin: EdgeInsets.only(top: 200), child: Text("${Provider.of<Counter>(context).value}"), ); } } class

Navigator routes Clear the stack of flutter

由 烈酒焚心 提交于 2021-02-06 14:20:37
问题 In my app i have three screens login , verifyotp , generatepass. I know how to move from one page to other page eg: Navigator.pushNamed(context, "/theNameOfThePage"); . I have a flow in which i move from login->verifyotp->generatepass my question is now how can i move from generatepass to login page and clearing all the stack. I am an android developer so in android we have intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK); . How can i achieve same result in

Flutter Camera Plugin

由 你说的曾经没有我的故事 提交于 2021-02-06 11:07:40
问题 I'm new to both Flutter and Dart, and I'm trying to use the Camera Plugin to understand how things work. All examples I find have this part: List<CameraDescription> cameras; Future<Null> main() async { cameras = await availableCameras(); runApp(new CameraApp()); } Is there some way I could do this inside the initState() method? I guess this is also a more general question regarding async work required before the initState -method is run. (As the initState -method cannot be async). My goal is

ScrollController how can I detect Scroll start, stop and scrolling?

由 二次信任 提交于 2021-02-06 10:12:32
问题 I'm using ScrollController for SingleChildScrollView widget where I want to detect when scroll start, end/stop and still scrolling? How can I detect, I'm using Listene scrollController = ScrollController() ..addListener(() { scrollOffset = _scrollController.offset; }); Also try with _scrollController.position.activity.velocity but didn't help me. Also there are _scrollController.position.didEndScroll(); _scrollController.position.didStartScroll(); But how can I use it? 回答1: From this link

ScrollController how can I detect Scroll start, stop and scrolling?

由 倾然丶 夕夏残阳落幕 提交于 2021-02-06 10:09:45
问题 I'm using ScrollController for SingleChildScrollView widget where I want to detect when scroll start, end/stop and still scrolling? How can I detect, I'm using Listene scrollController = ScrollController() ..addListener(() { scrollOffset = _scrollController.offset; }); Also try with _scrollController.position.activity.velocity but didn't help me. Also there are _scrollController.position.didEndScroll(); _scrollController.position.didStartScroll(); But how can I use it? 回答1: From this link

Flutter - How does MultiProvider work with providers of the same type?

由 帅比萌擦擦* 提交于 2021-02-06 09:10:29
问题 For example, I am trying to obtain data emitted for multiple streams at once, but 2 or more of these streams emit data of the same type, lets say a string. My question is, is it possible to use MultiProvider and use multiple StreamProvider (or any provider, but I am interested in this case) of the same type while still being able to access the data emitted by each one of them? A solution for this is using a StreamBuilder when using common data types but I really like what the MultiProvider

Flutter - How does MultiProvider work with providers of the same type?

由 百般思念 提交于 2021-02-06 09:07:52
问题 For example, I am trying to obtain data emitted for multiple streams at once, but 2 or more of these streams emit data of the same type, lets say a string. My question is, is it possible to use MultiProvider and use multiple StreamProvider (or any provider, but I am interested in this case) of the same type while still being able to access the data emitted by each one of them? A solution for this is using a StreamBuilder when using common data types but I really like what the MultiProvider

Flutter - How does MultiProvider work with providers of the same type?

由 痞子三分冷 提交于 2021-02-06 09:07:24
问题 For example, I am trying to obtain data emitted for multiple streams at once, but 2 or more of these streams emit data of the same type, lets say a string. My question is, is it possible to use MultiProvider and use multiple StreamProvider (or any provider, but I am interested in this case) of the same type while still being able to access the data emitted by each one of them? A solution for this is using a StreamBuilder when using common data types but I really like what the MultiProvider

Flutter - How does MultiProvider work with providers of the same type?

由 你离开我真会死。 提交于 2021-02-06 09:06:12
问题 For example, I am trying to obtain data emitted for multiple streams at once, but 2 or more of these streams emit data of the same type, lets say a string. My question is, is it possible to use MultiProvider and use multiple StreamProvider (or any provider, but I am interested in this case) of the same type while still being able to access the data emitted by each one of them? A solution for this is using a StreamBuilder when using common data types but I really like what the MultiProvider

how can I make BottomNavigationBar stick on top of keyboard flutter

由 随声附和 提交于 2021-02-06 08:36:52
问题 I am trying to make a simple chat app, so I created a scaffold and my body, will be the messages and my bottomNavigationBar would be my typing field and sending icon. I added a text field but when typing the navigation bar is hidden by the keyboard. this is the code of my BottomNavigationBar : bottomNavigationBar: new Container( height: ScreenSize.height/12, /*color: Colors.red,*/ child: new Row( mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: <Widget>[ new Column(
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