flutter-layout

问题 I am creating a checkbox field every time i press a button. but the generated checkbox is not changing the state when pressed, instead the next checkbox which is generated comes with the changed state. I have attached the video of how it is working currently (https://imgur.com/a/75vE5cj ) my entire code goes like this : class ToDoNotes extends StatelessWidget { @override Widget build(BuildContext context) { SizeConfig().init(context); return new MaterialApp( title: 'notes', theme: new

问题 I am trying to get a container to be exactly half the screen height[after considering the AppBar height] and half the screen width. This is what I came up with... class App extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(), body: Column( crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[ Flexible( child: Container( width: MediaQuery.of(context).size.width / 2, color: Colors.red, ), ), Flexible( flex: 1, child: Container()

问题 I am trying to get a container to be exactly half the screen height[after considering the AppBar height] and half the screen width. This is what I came up with... class App extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(), body: Column( crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[ Flexible( child: Container( width: MediaQuery.of(context).size.width / 2, color: Colors.red, ), ), Flexible( flex: 1, child: Container()

问题 Is it possible to create an animation in flutter that doesn't continously change its value, but only with a given time gaps? I have the following code working right now, but i'm sure there is a better solution out there. int aniValue = 0; bool lock = false; _asyncFunc() async { if(lock) return; else lock = true; await new Future.delayed(const Duration(milliseconds: 50), () { ++aniValue; if (aniValue == 41) { aniValue = 0; } }); lock = false; setState(() {}); _asyncFunc(); } 回答1: It is

问题 Is it possible to create an animation in flutter that doesn't continously change its value, but only with a given time gaps? I have the following code working right now, but i'm sure there is a better solution out there. int aniValue = 0; bool lock = false; _asyncFunc() async { if(lock) return; else lock = true; await new Future.delayed(const Duration(milliseconds: 50), () { ++aniValue; if (aniValue == 41) { aniValue = 0; } }); lock = false; setState(() {}); _asyncFunc(); } 回答1: It is

问题 Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[ Container( margin: EdgeInsets.only(bottom: 400.0), child: Center( child: Padding( padding: EdgeInsets.symmetric(horizontal: 10.0), child: Text( _text, style: TextStyle(color: Colors.white), ), ), ), ), ... 来源： https://stackoverflow.com/questions/59777112/when-i-use-margin-it-work-fine-container-is-going-up-but-its-taking-a-lot-of-sp

问题 I've try to put a Column(a Container inside) in SliverAppBar bottom property as a button, but it can't overlap the ExtentList ,just overflow the bottom margin. I want to make it overlapped just like Spotify App do. this is Spotify Sample: https://imgur.com/VrZRY4c this is what I've tried: https://imgur.com/4bNZw8j My code: class _MenuListState extends State<MenuList> { @override Widget build(BuildContext context) { return Scaffold( body: CustomScrollView( slivers: <Widget>[ SliverPadding(

问题 I want to keep the widget's state in Scaffold.drawer . The Scaffold.drawer is a custom widget, which has a RaiseButton in it. When click the button, the text in the button changed. But when the drawer is closed, and reopen the drawer, the changed text is reseted. I have use " with AutomaticKeepAliveClientMixin<> " in my custom Drawer , but it does't work. import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget { @override Widget build

问题 In flutter, TextField doesn't have an intrinsic width; it only knows how to size itself to the full width of its parent container. How do I set the width to the width of the contained text. I tried putting the TextField inside a container As outlined here How to update flutter TextField's height and width? new Container( width: 100.0, child: new TextField() ) I expect the width of the TextField to match the width of the text it contains. The TextField should grow wider as text is typed, and

问题 I'am trying to add TextField to a Dialog, but when the Keyboard appears, it gives an overflow. My dialog Image When the Keyboard shows up Here How a part my code looks Like: AlertDialog( content: new ListView( shrinkWrap: true, children: <Widget>[ Text( "How Would You Rate Our App?", style: TextStyle(fontSize: 16.0, fontWeight: FontWeight.bold), textAlign: TextAlign.center, ) 回答1: You can simply use SingleChildScrollView: AlertDialog( content: SingleChildScrollView( scrollDirection: Axis