我正在做一个餐厅菜单的应用程序，我被卡在程序的顺序。我试图在MYSQL数据库中存储食物项目的列表，当按钮下单时。我想我知道存储列表的概念，但不能做到这一点。我试图循环通过列表中的食品项目，并得到列表中所有食品项目的名称和数量，对列表进行编码，并使用post request来存储数据。
这个类是Place Order，我在这里完成了订单过程。
import 'package:bloc_pattern/bloc_pattern.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:menu_app/Regular/regularItems.dart';
import 'cartListBloc.dart';
import 'dart:convert'; //to convert http response in json format
import 'package:http/http.dart' as http;
class Cart extends StatefulWidget {
const Cart({Key key}) : super(key: key);
@override
_CartState createState() => _CartState();
}
class _CartState extends State<Cart> {
List<FoodItem> foodItems = new List<FoodItem>();
var listUpdate = false;
@override
Widget build(BuildContext context) {
final CartListBloc bloc = BlocProvider.getBloc<CartListBloc>();
return BlocProvider(
blocs: [Bloc((i) => CartListBloc())],
child: StreamBuilder(
stream: bloc.listStream,
builder: (context, snapshot) {
if (snapshot.data != null) {
if (!listUpdate) {
foodItems = snapshot.data;
}
return Scaffold(
appBar: AppBar(
leading: Icon(Icons.add_shopping_cart),
backgroundColor: Colors.brown,
title: Text('Food Cart'),
centerTitle: true,
),
body: SafeArea(
child: CartBody(foodItems, updateList),
),
bottomNavigationBar: BottomBar(foodItems, updateList),
);
} else {
return Container();
}
},
));
}
void updateList(List<FoodItem> list) {
setState(() {
listUpdate = true;
foodItems = list;
});
}
}
class BottomBar extends StatelessWidget {
// final List<FoodItem> foodItems;
List<FoodItem> foodItems;
Function updateList;
BottomBar(this.foodItems, this.updateList);
@override
Widget build(BuildContext context) {
return Container(
margin: EdgeInsets.only(left: 0, bottom: 15),
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
totalAmount(foodItems),
Divider(
height: 5,
color: Colors.brown,
),
PlaceOrder(),
],
),
);
}
Container totalAmount(List<FoodItem> foodItems) {
return Container(
margin: EdgeInsets.only(right: 10),
padding: EdgeInsets.all(25),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
"Total:",
style: TextStyle(fontSize: 25, fontWeight: FontWeight.w300),
),
Text(
"\Rs ${returnTotalAmount(foodItems)}",
style: TextStyle(fontWeight: FontWeight.w700, fontSize: 25),
),
],
),
);
}
String returnTotalAmount(List<FoodItem> foodItems) {
double totalAmount = 0.0;
for (int i = 0; i < foodItems.length; i++) {
totalAmount = totalAmount + foodItems[i].price * foodItems[i].Quantity;
}
return totalAmount.toStringAsFixed(2);
}
}
class CartBody extends StatelessWidget {
CartBody(this.foodItems, this.updateList);
final List<FoodItem> foodItems;
Function updateList;
@override
Widget build(BuildContext context) {
return Container(
padding: EdgeInsets.fromLTRB(5, 0, 0, 0),
child: Center(
child: Column(
children: <Widget>[
Table(),
//CustomBar(),
SizedBox(
height: 30,
),
Expanded(
flex: 1,
child: foodItems.length > 0 ? foodItemList() : noItemContainer(),
)
],
),
),
);
}
Container noItemContainer() {
return Container(
child: Center(
child: Text(
"No food item in the cart.",
style: TextStyle(
color: Colors.black26,
fontSize: 25,
fontStyle: FontStyle.italic,
fontFamily: 'Rancho-Regular',
),
)));
}
ListView foodItemList() {
return ListView.builder(
itemCount: foodItems.length,
itemBuilder: (context, index) {
return ItemContent(
foodItem: foodItems[index],
foodItems: foodItems,
updateList: updateList,
index: index);
},
);
}
}
class CustomQuantity extends StatefulWidget {
final FoodItem foodItem;
List<FoodItem> foodItems;
Function updateList;
int index;
CustomQuantity(this.foodItem, this.foodItems, this.updateList, this.index);
@override
_CustomQuantityState createState() => _CustomQuantityState();
}
class _CustomQuantityState extends State<CustomQuantity> {
final double _buttonWidth = 28;
final CartListBloc bloc = BlocProvider.getBloc<CartListBloc>();
removeFromList(FoodItem foodItems) {
bloc.removeFromList(foodItems);
}
@override
Widget build(BuildContext context) {
return Container(
decoration: BoxDecoration(
border: Border.all(color: Colors.black, width: 2),
borderRadius: BorderRadius.circular(10),
),
padding: EdgeInsets.all(4),
width: 90,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
SizedBox(
width: _buttonWidth,
height: _buttonWidth,
child: FlatButton(
padding: EdgeInsets.all(0),
onPressed: () {
// setState(() {});
if (widget.foodItems[widget.index].Quantity > 1) {
widget.foodItems[widget.index].Quantity--;
print(widget.foodItems[widget.index].Quantity);
print(widget.foodItem.Quantity * widget.foodItem.price);
} else {
removeFromList(widget.foodItems[widget.index]);
print('remove');
}
widget.updateList(widget.foodItems);
// return widget.cart.foodItems[widget.index].quantity;
},
child: Text(
"-",
style: TextStyle(
fontWeight: FontWeight.w600,
fontSize: 35,
color: Colors.brown),
),
),
),
Text(
widget.foodItems[widget.index].Quantity.toString(),
style: TextStyle(
fontWeight: FontWeight.w600, fontSize: 20, color: Colors.brown),
),
SizedBox(
width: _buttonWidth,
height: _buttonWidth,
child: FlatButton(
padding: EdgeInsets.all(0),
onPressed: () {
// setState(() {
// print(widget.foodItem.quantity);
// print(widget.foodItem.quantity * widget.foodItem.price);
// });
widget.foodItems[widget.index].Quantity++;
widget.updateList(widget.foodItems);
// return widget.cart.foodItems[widget.index].quantity;
},
child: Text(
"+",
style: TextStyle(
fontWeight: FontWeight.w600,
fontSize: 30,
color: Colors.brown),
),
),
),
],
),
);
}
}
class ItemContent extends StatelessWidget {
const ItemContent(
{Key key,
@required this.foodItem,
this.foodItems,
this.updateList,
this.index})
: super(key: key);
final FoodItem foodItem;
final List<FoodItem> foodItems;
final int index;
final Function updateList;
@override
Widget build(BuildContext context) {
var customQuantity = CustomQuantity(foodItem, foodItems, updateList, index);
return Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
ClipRRect(
borderRadius: BorderRadius.circular(5),
child: Image.asset(
'system/public/foodItems/' + foodItem.image,
fit: BoxFit.fitHeight,
height: 50,
width: 70,
),
),
RichText(
text: TextSpan(
style: TextStyle(
fontSize: 21,
fontFamily: 'Rancho-regular',
color: Colors.brown,
fontWeight: FontWeight.w700),
children: [
TextSpan(
text: foodItem.Name,
),
]),
),
CustomQuantity(foodItem, foodItems, updateList, index),
Text("\Rs ${foodItem.price * customQuantity.foodItem.Quantity}",
style: TextStyle(
color: Colors.black,
fontWeight: FontWeight.w400,
fontFamily: 'Rancho-regular',
fontSize: 21)),
],
),
),
);
}
}
class Table extends StatelessWidget {
const Table({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
var tableController = TextEditingController(text: ' Table-1');
return Container(
child: Padding(
padding: EdgeInsets.fromLTRB(130, 0, 130, 0),
child: TextFormField(
controller: tableController,
enabled: false,
style: TextStyle(
color: Colors.brown,
fontWeight: FontWeight.bold,
fontSize: 22,
fontFamily: 'Rancho-Regular'),
),
),
);
}
}
class PlaceOrder extends StatefulWidget {
static final url = 'http://192.168.254.2:8000/api/order/';
const PlaceOrder({Key key}) : super(key: key);
@override
_PlaceOrderState createState() => _PlaceOrderState();
}
class _PlaceOrderState extends State<PlaceOrder> {
//converting list into an Json Array
List encondeToJson(List<FoodItem> foodItems) {
List jsonList = List();
foodItems.map((item) => jsonList.add(item.toJson())).toList();
return jsonList;
}
List<FoodItem> loopForOrder(List<FoodItem> foodItems) {
for (int i = 0; i < foodItems.length; i++) {
foodItems = [
FoodItem(Name: foodItems[i].Name, Quantity: foodItems[i].Quantity)
];
}
print(foodItems.length);
print('order completed');
return encondeToJson(foodItems);
}
//var foodItems= [FoodItem(Name: 'Cheese Burger',Quantity: 3),FoodItem(Name: 'Lemon Mojito',Quantity: 1)];
var tableController = TextEditingController(text: 'Table-1');
bool visible = false;
Future requestOrder() async {
final response = await http.post(
'http://192.168.254.2:8000/api/order/',
headers: {
'Content-Type': 'application/json',
},
body: jsonEncode({
'tableNo': tableController.text,
'status': 0,
'cart': loopForOrder,
}),
);
print(loopForOrder);
//print(loopForOrder.length);
print('statuscode = ' + response.statusCode.toString());
return loopForOrder;
}
Future<void> confirmation() async {
return showDialog<void>(
context: context,
barrierDismissible: false, // user must tap button!
builder: (BuildContext context) {
return AlertDialog(
title: Text('Order placement confirmation.',
style: TextStyle(
fontFamily: 'Lobster-regular',
fontSize: 18,
)),
content: Text('Do you wish to place order?',
style: TextStyle(fontFamily: 'Lobster-regular', fontSize: 14)),
actions: <Widget>[
Visibility(
visible: visible,
child: Container(child: CircularProgressIndicator())),
FlatButton(
onPressed: requestOrder,
child: Text('Yes',
style: TextStyle(
color: Colors.black,
fontFamily: 'Lobster-regular',
fontSize: 20)),
),
FlatButton(
onPressed: () {
Navigator.of(context).pop();
},
child: Text('No',
style: TextStyle(
color: Colors.black,
fontFamily: 'Lobster-regular',
fontSize: 20))),
],
elevation: 24,
backgroundColor: Colors.white,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(40.0))),
//shape: CircleBorder(),
);
},
);
}
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.fromLTRB(20, 0, 15, 0),
child: RaisedButton(
color: Colors.grey[400],
elevation: 18,
onPressed: confirmation,
child: Text('Place Order',
style: TextStyle(
color: Colors.brown,
fontWeight: FontWeight.bold,
fontSize: 22,
fontFamily: 'Rancho-Regular',
)),
shape: RoundedRectangleBorder(
borderRadius: new BorderRadius.circular(15),
side: BorderSide(color: Colors.brown, width: 2),
),
),
),
// Visibility(
// visible: visible,
// child: Container(child: CircularProgressIndicator())),
],
);
}
}
这是很难知道哪里是你的代码不工作，因为你是粘贴整个代码.我假设这一点，但你有问题建立的POST请求？
class OrderRequest{
String tableNo;
int status;
List<FoodItem> cart;
OrderRequest({this.tableNo,this.status,this.cart});
Map toMap() {
var map = new Map<String, dynamic>();
map['tableNo'] = tableNo;
map['status'] = status;
map['cart'] = cart;
return map;
}
}
然后，你可以做这样的请求。
static Future<String> apiRequest(String url, Map jsonMap) async {
HttpClient httpClient = new HttpClient();
HttpClientRequest request = await httpClient.postUrl(Uri.parse(url));
request.headers.set('content-type', 'application/json');
request.add(utf8.encode(json.encode(jsonMap)));
HttpClientResponse response = await request.close();
// todo - you should check the response.statusCode
String reply = await response.transform(utf8.decoder).join();
httpClient.close();
return reply;}
我希望这能帮助你