Flutter 搜索代理,当我点击搜索按钮时,它会显示红色屏幕,带有错误子项=无效的
我通过search delegate创建了一个搜索选项,但当我单击search按钮时,它会显示一个红色屏幕,并显示以下错误:“在生成SearchPage时抛出了以下断言(脏,依赖项:[[u LocalizationsScope-[GlobalKey#69e74],_InheritedTheme],状态:_SearchPageState#72bb6):'package:flatter/src/widgets/basic.dart':失败的断言:第6938行第15位:“child!=null”:不正确Flutter 搜索代理,当我点击搜索按钮时,它会显示红色屏幕,带有错误子项=无效的,flutter,dart,flutter-layout,flutter-dependencies,flutter-web,Flutter,Dart,Flutter Layout,Flutter Dependencies,Flutter Web,我通过search delegate创建了一个搜索选项,但当我单击search按钮时,它会显示一个红色屏幕,并显示以下错误:“在生成SearchPage时抛出了以下断言(脏,依赖项:[[u LocalizationsScope-[GlobalKey#69e74],_InheritedTheme],状态:_SearchPageState#72bb6):'package:flatter/src/widgets/basic.dart':失败的断言:第6938行第15位:“child!=null”:不正
import 'package:flutter/material.dart';
import 'package:grk_001/screen/main_screen.dart';
import 'widgets/entry_item.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import 'package:grk_001/screen/favourite_screen.dart';
import 'package:grk_001/Provider/Auth.dart';
import 'package:provider/provider.dart';
import 'package:grk_001/Provider/cart.dart';
import 'package:grk_001/widgets/badge.dart';
import 'package:grk_001/screen/cart_screen.dart';
import 'package:grk_001/widgets/drawer.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:grk_001/models/main_screen_categories_entry.dart';
class HomeScreen extends StatefulWidget {
static const String routename = 'homescreen';
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
final GlobalKey<ScaffoldState> _scaffoldkey = GlobalKey<ScaffoldState>();
FirebaseUser Loggedinuser;
@override
void didChangeDependencies() {
// TODO: implement didChangeDependencies
Future.delayed(Duration.zero).then((_) async {
await Provider.of<Auth>(context, listen: false).getcurrentuser();
});
super.didChangeDependencies();
}
@override
Widget build(BuildContext context) {
final devicesize = MediaQuery.of(context).size;
return SafeArea(
child: Scaffold(
key: _scaffoldkey,
appBar: AppBar(
leading: IconButton(
onPressed: () {
_scaffoldkey.currentState.openDrawer();
},
icon: Icon(
Icons.list,
color: Colors.white,
size: 35.0,
),
),
bottom: PreferredSize(
preferredSize: const Size.fromHeight(50.0),
child: Container(
padding: const EdgeInsets.all(8.0),
child: Row(
children: <Widget>[
const SizedBox(
width: 10.0,
),
Expanded(
child: GestureDetector(
onTap: () {
_scaffoldkey.currentState.openEndDrawer();
},
child: Container(
padding: const EdgeInsets.all(8.0),
alignment: Alignment.center,
height: 40.0,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(5.0),
),
child: Text(
'Categories',
),
),
),
),
],
),
),
),
title: Text('HomeScreen'),
actions: <Widget>[
IconButton(
icon: Icon(Icons.search),
onPressed: () {
showSearch(context: context, delegate: DataSearch());
},
),
IconButton(
icon: Icon(
FontAwesomeIcons.heart,
size: 30.0,
),
tooltip: 'My Wish List',
onPressed: () {
Navigator.pushNamed(context, FavouriteScreen.routename);
},
),
IconButton(
icon: Icon(
Icons.notifications,
size: 30.0,
),
tooltip: 'My Notifications',
onPressed: () {},
),
Consumer<Cart>(
builder: (_, cartdata, ch) => Badge(
child: ch,
value: cartdata.itemcount.toString(),
),
child: IconButton(
onPressed: () {
Navigator.pushNamed(context, CartScreen.routename);
},
icon: Icon(
Icons.shopping_cart,
size: 40.0,
),
),
),
],
),
body: MainScreen(),
// body: CategoryScreen(),
endDrawer: Drawer(
child: Column(
children: <Widget>[
Container(
color: Color(0XFFFF4081),
height: devicesize.height * 0.10,
child: DrawerHeader(
margin: EdgeInsets.zero,
child: InkWell(
onTap: () {
Navigator.of(context).pop();
},
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Icon(
Icons.apps,
color: Colors.white,
),
SizedBox(
width: 10.0,
),
Text(
'Categories',
style:
TextStyle(color: Colors.white, fontSize: 20.0),
),
],
),
)
// child: Text('Categories'),
),
),
Container(
height: devicesize.height * 0.85,
child: ListView.builder(
itemBuilder: (context, index) => EntryItem(data[index]),
itemCount: data.length,
),
)
],
),
),
drawer: Container(
width: devicesize.width * 0.65,
child: DrawerItem(devicesize, context),
),
),
);
}
}
class DataSearch extends SearchDelegate<String> {
final statelist = [
'Andaman and Nicobar Islands',
' Andhra Pradesh',
'Arunachal Pradesh',
'Assam',
'Bihar',
'Chandigarh ',
'Chhattisgarh',
'Dadra and Nagar Havel',
'Daman and Diu',
'Delhi',
'Goa',
'Gujrat',
'Haryana',
'Himachal Pradesh',
'Uttar Pradesh',
'Uttarakhand',
'West Bengal',
'Sikkim',
'Meghalya',
'Mizoram',
];
final recentlist = ['Modingar', 'Ghaziabad', 'Merrut', 'Hapur', 'Delhi'];
@override
List<Widget> buildActions(BuildContext context) {
// action for app bar
return [
IconButton(
onPressed: () {
query = "";
},
icon: Icon(Icons.clear),
)
];
}
@override
Widget buildLeading(BuildContext context) {
// leading icon on the left of the app bar
return IconButton(
icon: AnimatedIcon(
icon: AnimatedIcons.menu_arrow,
progress: transitionAnimation,
),
onPressed: () {
close(context, null);
},
);
}
@override
Widget buildResults(BuildContext context) {
// TODO: implement buildResults
return Container(
height: 150.0,
child: Card(
color: Colors.red,
shape: StadiumBorder(),
child: Text(query),
),
);
}
@override
Widget buildSuggestions(BuildContext context) {
// TODO: implement buildSuggestions
final suggestionList = query.isEmpty
? recentlist
: statelist.where((element) => element.startsWith(query)).toList();
ListView.builder(
itemBuilder: (context, index) => ListTile(
onTap: () {
showResults(context);
},
title: RichText(
text: TextSpan(
text: suggestionList[index].substring(0, query.length),
style: TextStyle(
color: Colors.black,
fontWeight: FontWeight.bold,
),
children: [
TextSpan(
text: suggestionList[index].substring(query.length),
style: TextStyle(color: Colors.grey))
]),
)),
itemCount: suggestionList.length,
);
}
}
导入“包装:颤振/材料.省道”;
导入“包装:grk_001/screen/main_screen.dart”;
导入“widgets/entry_item.dart”;
导入“package:font_awesome_flatter/font_awesome_flatter.dart”;
导入“包装:grk_001/screen/favorite_screen.dart”;
导入“包:grk_001/Provider/Auth.dart”;
导入“包:provider/provider.dart”;
导入“包:grk_001/Provider/cart.dart”;
导入“包:grk_001/widgets/badge.dart”;
导入“包装:grk_001/screen/cart_screen.dart”;
导入“包:grk_001/widgets/drawer.dart”;
导入“包:firebase_auth/firebase_auth.dart”;
导入“包:grk_001/models/main_screen_categories_entry.dart”;
类主屏幕扩展StatefulWidget{
静态常量字符串routename='主屏幕';
@凌驾
_HomeScreenState createState()=>\u HomeScreenState();
}
类_homescrenstate扩展状态{
最终GlobalKey _scaffoldkey=GlobalKey();
FirebaseUser日志用户;
@凌驾
void didChangeDependencies(){
//TODO:实现didChangeDependencies
Future.delayed(Duration.zero).then(u)async{
等待Provider.of(context,listen:false).getcurrentuser();
});
super.didChangeDependencies();
}
@凌驾
小部件构建(构建上下文){
final devicesize=MediaQuery.of(context).size;
返回安全区(
孩子:脚手架(
钥匙:_scaffoldkey,
appBar:appBar(
领先:IconButton(
已按下:(){
_scaffoldkey.currentState.openDrawer();
},
图标:图标(
图标列表,
颜色:颜色,白色,
尺寸:35.0,
),
),
底部:首选尺寸(
首选大小:常量大小。从高度(50.0),
子:容器(
填充:常数边集全部(8.0),
孩子:排(
儿童:[
常量大小框(
宽度:10.0,
),
扩大(
儿童:手势检测器(
onTap:(){
_scaffoldkey.currentState.openEndDrawer();
},
子:容器(
填充:常数边集全部(8.0),
对齐:对齐.center,
身高:40.0,
装饰:盒子装饰(
颜色:颜色,白色,
边界半径:边界半径。圆形(5.0),
),
子:文本(
“类别”,
),
),
),
),
],
),
),
),
标题:文本(“主屏幕”),
行动:[
图标按钮(
图标:图标(Icons.search),
已按下:(){
showSearch(上下文:context,委托:DataSearch());
},
),
图标按钮(
图标:图标(
Fontawee.heart,
尺寸:30.0,
),
工具提示:“我的愿望清单”,
已按下:(){
Navigator.pushNamed(上下文,FavoriteScreen.routename);
},
),
图标按钮(
图标:图标(
图标、通知、,
尺寸:30.0,
),
工具提示:“我的通知”,
按下:(){},
),
消费者(
建筑商:(u,cartdata,ch)=>徽章(
孩子:ch,,
值:cartdata.itemcount.toString(),
),
孩子:我的钮扣(
已按下:(){
Navigator.pushName(上下文,CartScreen.routename);
},
图标:图标(
图标。购物车,
尺寸:40.0,
),
),
),
],
),
主体:主屏幕(),
//正文:类别屏幕(),
收尾抽屉(
子:列(
儿童:[
容器(
颜色:颜色(0XFFFF4081),
高度:devicesize.height*0.10,
儿童:抽屉阅读器(
边距:EdgeInsets.zero,
孩子:InkWell(
onTap:(){
Navigator.of(context.pop();
},
孩子:排(
crossAxisAlignment:crossAxisAlignment.center,
mainAxisAlignment:mainAxisAlignment.start,
儿童:[
图标(
图标。应用程序,
颜色:颜色,白色,
),
大小盒子(
宽度:10.0,
),
正文(
“类别”,
风格:
TextStyle(颜色:Colors.white,字体大小:20.0),
),
],
),
)
//子项:文本(“类别”),
),
),
容器(
高度:devicesize.height*0.85,
子项:ListView.builder(
@override
Widget buildSuggestions(BuildContext context) {
// TODO: implement buildSuggestions
final suggestionList = query.isEmpty
? recentlist
: statelist.where((element) => element.startsWith(query)).toList();
return ListView.builder(
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text(widget.title), actions: <Widget>[
IconButton(
icon: Icon(Icons.search),
onPressed: () {
showSearch(context: context, delegate: DataSearch());
},
),
]),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
class DataSearch extends SearchDelegate<String> {
final statelist = [
'Andaman and Nicobar Islands',
' Andhra Pradesh',
'Arunachal Pradesh',
'Assam',
'Bihar',
'Chandigarh ',
'Chhattisgarh',
'Dadra and Nagar Havel',
'Daman and Diu',
'Delhi',
'Goa',
'Gujrat',
'Haryana',
'Himachal Pradesh',
'Uttar Pradesh',
'Uttarakhand',
'West Bengal',
'Sikkim',
'Meghalya',
'Mizoram',
];
final recentlist = ['Modingar', 'Ghaziabad', 'Merrut', 'Hapur', 'Delhi'];
@override
List<Widget> buildActions(BuildContext context) {
// action for app bar
return [
IconButton(
onPressed: () {
query = "";
},
icon: Icon(Icons.clear),
)
];
}
@override
Widget buildLeading(BuildContext context) {
// leading icon on the left of the app bar
return IconButton(
icon: AnimatedIcon(
icon: AnimatedIcons.menu_arrow,
progress: transitionAnimation,
),
onPressed: () {
close(context, null);
},
);
}
@override
Widget buildResults(BuildContext context) {
// TODO: implement buildResults
return Container(
height: 150.0,
child: Card(
color: Colors.red,
shape: StadiumBorder(),
child: Text(query),
),
);
}
@override
Widget buildSuggestions(BuildContext context) {
// TODO: implement buildSuggestions
final suggestionList = query.isEmpty
? recentlist
: statelist.where((element) => element.startsWith(query)).toList();
return ListView.builder(
itemBuilder: (context, index) => ListTile(
onTap: () {
showResults(context);
},
title: RichText(
text: TextSpan(
text: suggestionList[index].substring(0, query.length),
style: TextStyle(
color: Colors.black,
fontWeight: FontWeight.bold,
),
children: [
TextSpan(
text: suggestionList[index].substring(query.length),
style: TextStyle(color: Colors.grey))
]),
)),
itemCount: suggestionList.length,
);
}
}