如何在Flutter中将列表视图中的项目从一个类添加到另一个类？
我正在做一个项目，其中有一个班级，该班级有两个孩子。一个孩子包含一个TabView和一个子类TabViewChild，我在其中生成一个gridview。另一方面，两个子包含一个listView。所以问题是，当我单击gridview项目时，我将该项目的值传递给静态列表，并将该列表传递给其他类的listview。但是我不知道如何在单击的项目上更改该类的状态，或者由于我是Flutter的新手，如何以更好的方式完成此任务。我希望当人们单击任何gridview的项目时，该项目同时出现在列表视图中。
class ItemMenus {
int id;
String code;
String name;
String salePrice;
String photo;
String categoryName;
String percentage;
int quantity;
ItemMenus({this.id, this.code, this.name, this.salePrice, this.photo,
this.categoryName, this.percentage, this.quantity});
ItemMenus.fromJson(Map<String, dynamic> json)
:
id = int.parse(json['id']),
code = json['code'],
name = json['name'],
salePrice = json['sale_price'],
photo = json['photo'],
categoryName = json['category_name'],
percentage = json['percentage'];
@override
String toString() {
return 'ItemMenus{id: $id, code: $code, name: $name, salePrice: $salePrice, photo: $photo, categoryName: $categoryName, percentage: $percentage}';
}
}
import 'package:food_app/model/mdl_item_menus.dart';
class ItemMenuList{
List<ItemMenus> _itmMenuLst = [];
ItemMenuList._();
static final ItemMenuList instanceItmMenuLst = ItemMenuList._();
static ItemMenuList get instance => instanceItmMenuLst;
void addItem(ItemMenus im){
_itmMenuLst.add(im);
}
List<ItemMenus> get list => _itmMenuLst;
@override
String toString() {
return 'ItemMenuList{_itmMenuLst: $_itmMenuLst}';
}
}
import 'package:flutter/material.dart';
import 'package:food_app/database/tables/tbl_categories.dart';
import 'package:food_app/model/list/item_menu_list.dart';
import 'package:food_app/model/mdl_categories.dart';
import 'package:food_app/model/mdl_item_menus.dart';
import 'package:food_app/pos/tab_bar_view.dart';
class EPos extends StatefulWidget{
@override
_EPosState createState() => _EPosState();
}
class _EPosState extends State<EPos> {
final categoryDBHelper = TblCategories.categoriesInstance;
final ItemMenuList instance2 = ItemMenuList.instance;
String _orderType = 'Dine-In', _info = 'Table No. 1', _userName = 'ZiaUddin';
List<Categories> catLst = [];
List<ItemMenus> itmLst = [];
Future getCategories() async {
catLst.clear();
var categories = await categoryDBHelper.getCategories();
categories.forEach((element) {
catLst.add(Categories(
id: element['id'],
categoryName: element['category_name'],
description: element['description'],
userId: element['user_id'],
companyId: element['company_id'],
delStatus: element['del_status']));
});
catLst.forEach((element) {
print(element);
});
return catLst;
}
@override
void initState() {
// TODO: implement initState
super.initState();
// itmLst = instance2.list;
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
body: Column(
children: [
//#region AppBar
Container(
width: MediaQuery.of(context).size.width,
height: MediaQuery.of(context).size.height * 0.15,
color: Colors.redAccent,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Container(
margin: EdgeInsets.fromLTRB(8, 10, 0, 0),
decoration: BoxDecoration(
shape: BoxShape.rectangle,
borderRadius: BorderRadius.circular(20),
color: Colors.red,
),
child: Row(
children: [
Icon(
Icons.arrow_back,
color: Colors.white,
size: 25,
),
Padding(
padding: const EdgeInsets.fromLTRB(4, 8, 10, 8),
child: Text(
_orderType,
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.bold,
color: Colors.white,
fontFamily: 'Ubuntu',
letterSpacing: 2.0,
),
),
),
],
),
),
Container(
margin: EdgeInsets.fromLTRB(8, 10, 0, 0),
decoration: BoxDecoration(
shape: BoxShape.rectangle,
borderRadius: BorderRadius.circular(10),
color: Colors.red,
),
child: Padding(
padding: const EdgeInsets.fromLTRB(20, 8, 20, 8),
child: Text(
_info,
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.bold,
color: Colors.amberAccent,
fontFamily: 'Ubuntu',
letterSpacing: 2.0,
),
),
),
),
Container(
margin: EdgeInsets.only(top: 15, right: 5),
decoration: BoxDecoration(
shape: BoxShape.rectangle,
borderRadius: BorderRadius.circular(30),
color: Colors.red,
),
child: Row(
children: [
Padding(
padding: const EdgeInsets.fromLTRB(10, 8, 8, 8),
child: Text(
_userName,
overflow: TextOverflow.ellipsis,
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.normal,
color: Colors.white,
fontFamily: 'Ubuntu',
letterSpacing: 1.0,
),
),
),
CircleAvatar(
backgroundColor: Colors.red,
radius: MediaQuery.of(context).size.height * 0.041,
child: CircleAvatar(
radius: MediaQuery.of(context).size.height * 0.04,
backgroundImage: AssetImage('assets/user.png'),
),
),
],
),
),
],
),
),
//endregion
Expanded(
child: Row(
children: [
//# region Menu
Flexible(
flex: 1,
child: Container(
decoration: BoxDecoration(
color: Colors.yellowAccent,
shape: BoxShape.rectangle,
),
child: Column(
children: [
Expanded(
child: Container(
color: Colors.white,
child: FutureBuilder(
future: getCategories(),
builder: (context, snapShot) {
if (snapShot.connectionState ==
ConnectionState.none &&
snapShot.hasData == null) {
return Center(
child: CircularProgressIndicator());
}
return MaterialApp(
debugShowCheckedModeBanner: false,
home: DefaultTabController(
length: catLst.length,
child: Scaffold(
backgroundColor: Colors.white,
appBar: PreferredSize(
preferredSize:
Size.fromHeight(kToolbarHeight),
child: Container(
height: MediaQuery.of(context)
.size
.height *
0.1,
child: TabBar(
indicatorColor:
Colors.amberAccent,
isScrollable: true,
tabs: catLst
.map<Widget>((Categories c) {
return Tab(
icon: Icon(
Icons.style,
color: Colors.amberAccent,
size: 15,
),
child: Text(
c.categoryName
.toUpperCase(),
style: TextStyle(
color: Colors.black,
fontWeight:
FontWeight.w400,
),
),
);
}).toList(),
),
),
),
body: TabBarView(
children: catLst.map((Categories c) {
return TabBarViewChild(categoryName:c.categoryName,
callback: (){
setState(() {
instance2.addItem(ItemMenus(name: c.categoryName));
itmLst = instance2.list;
print('I am Callback');
});
},);
}).toList(),
),
),
),
);
}),
),
),
],
),
),
),
//endregion
//# region OrderList
Flexible(
flex: 1,
child: Container(
decoration: BoxDecoration(
color: Colors.white,
shape: BoxShape.rectangle,
),
child: ListView.builder(
itemCount: itmLst.length,
itemBuilder: (context, index){
return ListTile(
title: Text(itmLst[index].name),
);
},
),
),
),
//endregion
],
),
),
],
),
);
}
}
import 'package:flutter/material.dart';
import 'package:food_app/database/tables/tbl_item_menus.dart';
import 'package:food_app/model/list/item_menu_list.dart';
import 'package:food_app/model/mdl_item_menus.dart';
import 'package:food_app/pos/new_sale.dart';
class TabBarViewChild extends StatefulWidget {
String categoryName;
VoidCallback callback;
TabBarViewChild({Key key,@required this.categoryName, this.callback}) : super(key:key);
@override
_TabBarViewChildState createState() => _TabBarViewChildState();
}
class _TabBarViewChildState extends State<TabBarViewChild> {
final ItemMenuList instance1 = ItemMenuList.instance;
List<ItemMenus> itmLst = [];
final itemMenus = TblItemMenus.itemMenusInstance;
Future getSpecificItemMenus() async{
var items = await itemMenus.getSpecificItemMenus(widget.categoryName);
itmLst.clear();
items.forEach((e) {
itmLst.add(ItemMenus(id: e['id'], categoryName: e['category_name'], code: e['code'],
name: e['name'], percentage: e['percentage'], photo: e['photo'], quantity: e['quantity'],
salePrice: e['sale_price']));
});
for (var value in itmLst) {
print(value);
}
return itmLst;
}
@override
Widget build(BuildContext context) {
return Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
color: Colors.white,
child: FutureBuilder(
future: getSpecificItemMenus(),
builder: (context, snapShot) {
if (snapShot.connectionState == ConnectionState.none
&& snapShot.hasData == null) {
return Center(child: CircularProgressIndicator());
}
return GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 3),
scrollDirection: Axis.vertical,
itemCount: itmLst.length,
itemBuilder: (context, index){
return Padding(
padding: const EdgeInsets.all(5.0),
child: InkWell(
child: Card(
elevation: 4,
color: Colors.amberAccent,
child: Center(
child: Text(
itmLst[index].name.toUpperCase(),
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.red,
fontSize: 13,
fontWeight: FontWeight.w700,
fontFamily: 'Ubuntu',
letterSpacing: 1.0,
),
),
),
),
onTap: (){
// Provider.of<ProItemMenus>(context, listen: false).addNewItemInList(ItemMenus(name: itmLst[index].name.toUpperCase()));
instance1.addItem(ItemMenus(categoryName: itmLst[index].name.toUpperCase()));
print(itmLst[index].name.toUpperCase());
},
),
);
}
);
}
),
);
}
}
1 个答案:
答案 0 :(得分：0)
所以现在的问题是，有两个有状态的小部件。
当我们要在它们之间共享data或state时，基本上我们需要有更多的一个有状态Widget，它将成为它们的父级。 / p>
此术语称为这个问题，称为State Management。
当前有许多知名的State Management，例如Provider和Bloc。 Reference。
但是我个人建议使用Provider，它具有简单的语法和概念。
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