我正在尝试在 flutter 中创建一个屏幕，该屏幕有 3 行堆叠在一起，但我不断收到语法错误。我在正文、Rows 等中尝试了多个容器并不断收到语法错误，我尝试做的事情是不可能的吗？我认为 Rows 是可堆叠的，或者至少是一个主体中的容器。
这是代码：
import 'package:flutter/material.dart';
class Index extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return new Scaffold(
appBar: new AppBar(
backgroundColor: const Color(0xFF0099a9),
),
body: Row(
//ROW 1
children: [
Container(
color: Colors.orange,
margin: EdgeInsets.all(25.0),
child: FlutterLogo(
size: 60.0,
),
),
Container(
color: Colors.blue,
margin: EdgeInsets.all(25.0),
child: FlutterLogo(
size: 60.0,
),
),
Container(
color: Colors.purple,
margin: EdgeInsets.all(25.0),
child: FlutterLogo(
size: 60.0,
),
),
],
),
Row(
//ROW 2
children: …是否可以使用 VS Code 在连接到 Windows 10 计算机的 iPhone 上以调试模式模拟 Flutter 应用程序？当我输入它时，这一切听起来都不起作用:)
我想基于布尔值显示和隐藏 HomeCategory 对象。我目前有这个：
_isOn ? HomeCategory(0, Icons.check, Colors.blue[800], "Check In", [Task(0, "Check In", true),]) : "",
但是它会引发错误，因为如果它关闭，我将传递一个空字符串。我如何向它传递一个空对象或隐藏它？这是一个像这样的列表：
_isOn ? HomeCategory(0, Icons.check, Colors.blue[800], "Check In", [Task(0, "Check In", true),]) : "",
HomeCategory(1, Icons.chat_bubble, Colors.red, "Forums", [ Task(1, "Questions", true),]),
HomeCategory(2, Icons.star, Colors.blue[200], "Goals", [ Task(2, "Goals", true),]),
HomeCategory(3, Icons.monetization_on, Colors.orange[700], "Budget", [ Task(3, "Budget", true),]),
HomeCategory(4, Icons.shopping_basket, Colors.brown[300], "Shopping", [ Task(4, "Items", true),]),
HomeCategory(5, Icons.calendar_today, Colors.purple[900], "My Day & Calendar", [ Task(4, "Events", false),]),
HomeCategory(6, Icons.check_circle_outline, Colors.teal[700], "Check Out", [ Task(4, …我需要从没有实体框架的ASP.NET Core构建Web API。它是一个现有数据库，具有一些自定义存储过程，我们不希望使用EF。
我搜索了此主题，但找不到任何相关信息，这有可能吗？
class _CheckInState extends State<CheckIn> {
double _value = 0;
String _emotionalStatus = 'Happy';
bool didStartDrag = false;
double updatedDragDelta;
bool didEndDrag = false;
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: new LBAppBar().getAppBar(),
drawer: new LBDrawer().getDrawer(),
body:
SwipeDetector(
child: Container(
decoration: BoxDecoration(
gradient: new LinearGradient(
colors: [Color.fromRGBO(1,89,99, 1.0), Colors.grey],
begin: Alignment.bottomLeft,
end: Alignment.topRight
)
),
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Container(
margin: EdgeInsets.only(left: 30.0,top: 30.0, bottom: 70.0, right:30.0),
child :
Text(
'How are you …我们想在ListTile. 这是代码。它是我们正在修改的基本购物清单屏幕，因此我们希望删除图标旁边有一个收藏夹图标。我尝试将其添加为副标题，但将其放在行的中间。我尝试为孩子添加一行，但它从屏幕上删除了购物项目。
import 'package:flutter/material.dart';
import 'package:lightbridge_mobile/models/shopping_item.dart';
import 'package:lightbridge_mobile/models/user.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;
class Shopping extends StatefulWidget {
@override
_HomePageState createState() => _HomePageState();
final User user;
Shopping({Key key, @required this.user}) : super(key: key);
}
class _HomePageState extends State<Shopping> {
final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>
();
final TextEditingController _textEditingController =
TextEditingController();
List<ShoppingItem> items = [
ShoppingItem('Milk'),
ShoppingItem('Eggs'),
ShoppingItem('Fabric Softener'),
];
void initState() {
super.initState();
}
_onAddItemPressed() {
_scaffoldKey.currentState.showBottomSheet<Null>((BuildContext context) {
return Container(
decoration: BoxDecoration(color: …We have a Features class that we are trying to fill when a screen loads. Its an http call that returns the object. Im struggling with how to do this. All of our http calls are done on a button click:
here is the call
Future<Features> getFeatureStatus(String userID) async {
Features _features;
final response =
await http.post('http://url/api/Features',
headers: {"Content-Type": "application/json",
'Accept': 'application/json',},
body: json.encode({'userID' : userID }));
_features = Features.fromJson(json.decode(response.body));
return _features;
}
When i try to call it at …
我正在尝试更改颤振中选项卡栏的背景颜色，我尝试了以下方法（在本论坛上被接受为答案），但没有奏效：
这是代码
return new MaterialApp(
theme: new ThemeData(
brightness: Brightness.light,
primaryColor: Colors.pink[800], //Changing this will change the color of the TabBar
accentColor: Colors.cyan[600],
),
编辑 ：
当我更改主题数据颜色时，背景颜色不会改变。我试图在应用栏下方创建一个水平滚动子菜单，有人建议我使用 Tab 栏。
这是整个 dart 文件：
import 'package:flutter/material.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
class Index extends StatelessWidget {
//final User user;
// HomeScreen({Key key, @required this.user}) : super(key: key);
@override
Widget build(BuildContext context) {
// TODO: implement build
// String emoji = emojify(":cool:");
return new MaterialApp(
theme: new ThemeData(
brightness: Brightness.light,
primaryColor: Colors.white, //Changing this will change …香港专业教育学院尝试使用swipedetector插件进行颤动，以实现向右滑动的新屏幕的导航，但无法正常工作，不会引发任何错误，并且在调试时永远不会碰到断点。我查看了GestureDector，但不确定是否可以在向右滑动的Scenerio中使用它，我们希望在向右滑动屏幕时可以将其导航到屏幕。
@override
Widget build(BuildContext context){
return new Scaffold(
appBar : LBAppBar().getAppBar(),
//drawer: new LBDrawer().getDrawer(),
body: Container(
decoration: BoxDecoration(
gradient: new LinearGradient(
colors: [Color.fromRGBO(1,89,99, 1.0), Colors.grey],
begin: Alignment.bottomLeft,
end: Alignment.topRight
)
),
child:
SwipeDetector(
onSwipeRight: () {
Navigator.of(context).push(new MaterialPageRoute(builder: (BuildContext context) => new WidgetsPage())
); },
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children:[
Row(
children: [
Container(
margin: EdgeInsets.only(left: 20.0,top: 10.0, bottom: 10.0, right:30.0),
child: Column(
children: <Widget>[
Text("Hi ${user.firstName}, Today is " + formatDate(), style: new TextStyle( color: Colors.white70, fontWeight: FontWeight.bold, …有没有办法在flutter中打开原生手机上的视频通话功能？我看过 Agora 和其他人，但没有一个像我们需要的那样工作。